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THE EFFICACY OF SANITATION ON MICROBIOLOGICAL HAZARDS
IN READY-TO-EAT FOOD OUTLETS FROM SELECTED PRIMARY
MANUFACTURERS IN GAUTENG PROVINCE, SOUTH AFRICA.
by
ANDRÉ ALBERTUS LAMBRECHTS
Dissertation submitted in fulfilment of the requirements for the degree
Master of Technology: Environmental Health
in the Faculty of Applied Sciences
at the Cape Peninsula University of Technology
Supervisor: Dr. IS Human
Co-supervisor: Prof. JFR Lues
Cape Town November 2011
This thesis is the copyright of the
Cape Peninsula University of Technology
and may not be published or reproduced
without prior permission from the university.
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provided by Cape Peninsula University of Technology
ii
DECLARATION
I, ANDRÉ ALBERTUS LAMBRECHTS, declare that the contents of this
dissertation/thesis represent my own unaided work, and that the dissertation/thesis has
not previously been submitted for academic examination towards any qualification.
Furthermore, it represents my own opinions and not necessarily those of the Cape
Peninsula University of Technology.
Signed Date
iii
ABSTRACT
The retail sector in South Africa is increasingly evolving into a dynamic industry, driven
by changes in technology, saturating markets and globalisation. A major phenomenon in
South Africa has been the evolution of hypermarkets, which sell large quantities of
almost all consumer goods on a self-service basis. The South African consumers are
becoming increasingly health conscious and, as such, the demand for wellness foods,
health and convenience food has escalated. Convenience foods are expected to remain
popular with consumers and supermarkets and will therefore increase the amount of
ready-to-eat food items offered. As the retail industry has changed over the last two
decades, so has the epidemiology of foodborne illnesses, with an increase in the
incidence of bacterial infections caused by emerging organisms. In addition, there are
certain food safety issues specifically associated with ready-to-eat foods. In recent years,
incidences of enteric diseases associated with meat consumption have risen. The
emergence of several new foodborne diseases has led to an increased focus attention on
the issue of food safety by consumers and the industry. The most commonly implicated
foods in these disease outbreaks have been meat and dairy products.
The microbial load of eight convenience food manufacturing plants was determined by
firstly sampling stainless steel food contact surfaces after they had been cleaned and
sanitised at the end of a day‘s shift. The samples were analysed for Total Plate Count
(TPC), Escherichia coli, Salmonella species and Staphylococcus aureus and Listeria. The
results showed that 59 % of the total areas sampled for TPC failed to comply with the
legal requirements for food surfaces specified in the South African Health Act (< 100
cfu.cm-2
). Listeria was detected in 23 % of the samples taken and E.coli was found in 1.3
% of the samples, while S. aureus was not detected in any of the samples. Fifty percent
iv
of the plants applied conventional cleaning methods for cleaning and sanitation and the
remaining 50 % used the low-pressure foam (LPF) method.
The bacterial results of the two cleaning methods were statistically compared and a
statistically significant difference (P ≤ 0.05) was found between the TPC means of the
cleaning methods after cleaning. No statistically significant difference (P > 0.05) was
found in terms of the Listeria species counts after both cleaning processes. The LPF
method proved to be the superior cleaning option for reducing TPC counts.
Secondly surface samples were collected from washed and sanitised dominant hands of
food handlers and analysed for the presence of total plate counts, S. aureus and E. coli.
The study aimed to evaluate the efficacy of hand washing practices and sanitation before
commencing work. A total of 230 samples were collected, involving 100 % of the food
handlers in selected convenience food outlets. The highest bacterial count taken from
handswas 7.4 x 10-3
cfu.cm-2
and the lowest showed no detectable growth. Forty percent
of the TPC analysed complied with the legal limit of < 100 cfu.cm-2
and only 18 % of the
food handlers had no detectable bacteria present on their hands. One hand sample tested
positive for E. coli, which is generally viewed as an indication of faecal contamination.
S. aureus could not be detected on the hands of any of the food handlers. The results of
this study indicated that hand hygiene is unsatisfactory and underlined the importance of
further training to improve food handlers‘ knowledge of good hand washing practices.
The study also aimed to present data on the food hygiene knowledge and practices of
food handlers based on a representative sample from convenience food outlets in the
Gauteng area. The management, as well as food handlers, were interviewed without
prior announcement and managers were interviewed prior to starting their shifts,
v
followed by food handlers, after they had passed through the change room and hand wash
facilities. Although the majority of food handlers adhered to basic hygiene principles,
the results highlighted a need for proper and continuous training in hygiene practices, not
only for food handlers, but also for management. Furthermore, all food handlers should
adhere to a formal cleaning schedule and specific courses should be planned for food
handlers. Most training is done away from the workplace and the workers might find it
difficult to translate theory into practice. Although food safety training programmes are
essential, behavioural changes will not occur merely as a result of having received
training but rather continuous development of food handlers.
In conclusion, the popularity of convenience food is bound to increase with the growing
appeal for modern foods. Consumers in South Africa nowadays demand good quality
and safe products at a reasonable cost. Due to continuous time constraints, convenience
food is the food of the future for the working mother. It is clear that managing foodborne
disease is a challenge and an economic problem subject to various constraints. Food
safety has too often become a hit-or-miss gamble, with parents obliged to roll the dice
when it comes to the safety of their children‘s food and consumers in general. The food
industry therefore needs to improve food safety processes to prevent the contamination of
foods and use methods to ensure safe food for consumers. Better training, more testing
and better methods of tracking food must be utilised to verify that the processes are
working. This study endeavoured to add to the understanding and improvement of
hygiene processes as well as food handlers‘ practices in the convenience food industry in
the Gauteng Province.
vi
ACKNOWLEDGEMENTS
I wish to thank:
Dr. Izanne Human for her continuous support and motivation and enthusiasm over
the last two years to keep my research work on track.
Prof. Ryk Lues for his technical support and general assistance and guidance.
Mr. Frans de Foglio for proof reading the document.
Mrs. Valmé Stewart, Managing Director of Swift Micro Laboratories (Pty) Ltd. for
the financial support and the study leave granted to complete the research.
My two sons, Charl and Jean, for their understanding and allowing me the time off
to complete the research work.
Mariska, my wife, for her understanding, love, support and assistance with the
typing and layout of the document.
Above all, God for giving me the wisdom and knowledge to complete the research.
vii
TABLE OF CONTENTS
Declaration ii
Abstract iii
Acknowledgements vi
CHAPTER 1: GENERAL INTRODUCTION .....................................................................1
1.1 BACKGROUND ...........................................................................................................1
1.2 THE IMPORTANCE OF CLEANING AND SANITATION ..................................2
1.3 THE PRACTICES OF FOOD HANDLERS RELATED TO THE
PROCESSING OF CONVENIENCE FOOD ............................................................5
1.4 LEGISLATION APPLICABLE TO CONVENIENCE FOOD IN SOUTH
AFRICA.........................................................................................................................6
1.5 RATIONALE ................................................................................................................7
1.5.1 Aims of the study ........................................................................................................7
1.5.2 Research hypothesis ...................................................................................................8
1.5.3 Null hypothesis ...........................................................................................................8
1.5.4 Data interpretation ....................................................................................................8
1.5.5 Relevance of study ......................................................................................................8
1.6 REFERENCES .............................................................................................................9
CHAPTER 2: LOW-PRESSURE FOAM CLEANING COMPARED TO
CONVENTIONAL CLEANING FOR REMOVAL OF BACTERIA FROM
SURFACES ASSOCIATED WITH CONVENIENCE FOOD ..........................................11
2.1 ABSTRACT ................................................................................................................11
2.2 INTRODUCTION ......................................................................................................12
2.3 A SYNOPSIS OF SURFACE-RELATED BACTERIA .........................................13
2.4 MATERIALS AND METHODS ...............................................................................15
2.4.1 Sampling protocol ....................................................................................................15
2.5 MICROBIOLOGICAL ANALYSIS ........................................................................18
2.6 DATA ANALYSIS......................................................................................................18
2.6.1 Microbiological results for convenience food contact surfaces ............................19
2.7 CONCLUSION ...........................................................................................................27
2.8 REFERENCES ...........................................................................................................28
viii
CHAPTER 3: MICROBIOLOGICAL CONTAMINATION ON THE HANDS OF
FOOD HANDLERS AS AN INDICATOR OF HAND WASHING EFFICACY IN THE
CONVENIENCE FOOD INDUSTRY IN SOUTH AFRICA ............................................34
3.1 ABSTRACT ................................................................................................................34
3.2 INTRODUCTION ......................................................................................................35
3.3 MATERIALS AND METHODS ...............................................................................37
3.3.1 Sampling protocol ....................................................................................................37
3.3.2 Microbiological analysis ..........................................................................................39
3.3.3 Microbiological results of convenience food worker’s hands ..............................39
3.4 CONCLUSION ...........................................................................................................46
3.5 REFERENCES ...........................................................................................................47
CHAPTER 4: FOOD HYGIENE KNOWLEDGE AND PRACTICES OF FOOD
HANDLERS IN THE CONVENIENCE FOOD INDUSTRY IN THE GAUTENG
PROVINCE, SOUTH AFRICA ............................................................................................51
4.1 ABSTRACT ................................................................................................................51
4.2 INTRODUCTION ......................................................................................................52
4.3 MATERIALS AND METHODS ...............................................................................54
4.3.1 Pilot study .................................................................................................................54
4.3.2 Sampling protocol ....................................................................................................54
4.3.3 Questionnaire design ...............................................................................................55
4.3.4 During the interview ................................................................................................55
4.3.5 Data analysis .............................................................................................................56
4.4 RESULTS AND DISCUSSION .................................................................................56
4.4.1 Level of management involvement .........................................................................56
4.4.2 Bacteriological safety of the food product .............................................................59
4.4.3 Knowledge and practices of food handlers ............................................................62
4.5 CONCLUSION ...........................................................................................................67
4.6 REFERENCES ...........................................................................................................69
CHAPTER 5: GENERAL DISCUSSIONS .........................................................................72
5.1 INTRODUCTION ......................................................................................................72
5.2 COMPARISONS BETWEEN LOW-PRESSURE FOAM CLEANING AND
CONVENTIONAL CLEANING TO REMOVE SELECTED BACTERIAL
PATHOGENS FROM SURFACES ASSOCIATED WITH CONVENIENCE
FOOD...........................................................................................................................73
5.3 MICROBIOLOGICAL CONTAMINATION ON THE HANDS OF
CONVENIENCE FOOD HANDLERS AS AN INDICATOR OF HAND
WASHING EFFICACY IN THE CONVENIENCE FOOD INDUSTRY ............74
5.4 FOOD HYGIENE KNOWLEDGE AND PRACTICES OF FOOD HANDLERS
ix
IN THE CONVENIENCE FOOD INDUSTRY IN THE GAUTENG
PROVINCE .................................................................................................................75
5.5 CONCLUDING REMARKS .....................................................................................76
5.6 RECOMMENDATIONS TO GOVERNANCE AND AUDIT BODIES ...............77
5.7 RECOMMENDATIONS TO INDUSTRY...............................................................77
5.8 FUTURE RESEARCH ..............................................................................................78
5.9 REFERENCES ...........................................................................................................79
APPENDIX A .........................................................................................................................81
APPENDIX B .........................................................................................................................83
x
LIST OF FIGURES
Figure 2.1: A comparison between the average Total Plate Count
versus the legal limit of < 100 cfu.cm-2
across
manufacturing plants.
20
Figure 2.2: Total samples analysed for the presence or absence of
Total Plate Counts, Escherichia coli, Staphylococcus
aureus, Salmonella species and Listeria species that were
collected from convenience food contact surfaces in eight
food manufacturing plants.
24
Figure 3.1: Comparison between the standard deviation and the
average Total Plate Count versus the legal limit of < 100
cfu.cm-2
.
41
Figure 3.2: Total samples analysed for the presence or absence of
Total Plate Count, Escherichia coli and Staphylococcus
aureus that were collected from workers‘ cleaned and
sanitised dominant hand surfaces in eight convenience
food manufacturing plants.
42
Figure 4.1: Hand washing procedures followed by food handlers. 60
Figure 4.2: Frequency of hand washing indicating non-compliance
of hand washing practices.
63
Figure 4.3: Food handlers‘ knowledge regarding specific personal
and hygiene procedures.
64
xi
LIST OF TABLES
Table 2.1: Distribution of total samples collected from convenience
food contact surfaces at eight food manufacturing plants.
17
Table 2.2: The distribution of organisms according to
compliance/non-compliance and occurrence.
21
Table 2.3: Statistical significance between conventional cleaning
and low-pressure foam cleaning methods used on
convenience food contact surfaces at eight food
manufacturing plants in terms of Total Plate Count.
26
Table 3.1: Distribution of samples collected from hands. 38
Table 3.2: The distribution of compliance in terms of Total Plate
Count compared to the legislated limit.
45
Table 4.1: Food safety assessment indicating compliance with food
safety standards.
57
Table 4.2: Food safety assessment indicating compliance with
general cleaning and hygiene principles.
58
Table 4.3: Bacteriological risk assessment. 61
Table 4.4: Food handlers‘ knowledge of good cleaning practices. 66
1
CHAPTER 1: GENERAL INTRODUCTION
1.1 BACKGROUND
The South African food and beverage market is becoming increasingly sophisticated and
retail outlets in South Africa offer the full spectrum of products available in the United
States of America. About 90 % of inventories of consumer-ready products in these stores
are domestically sourced. A major phenomenon in South Africa has been the evolution of
hypermarkets, which sell large quantities of almost all consumer goods on a self-service
basis. The hypermarkets, located mostly in suburban shopping centres or malls, have put
significant pricing pressure on smaller scale local retailers by purchasing directly from
manufacturers and bypassing the wholesaler, thereby obtaining lower margins but a higher
turnover. The South African consumer is becoming increasingly health conscious and, as
such, the demand for wellness foods, health and convenience food has escalated/grown.
Convenience foods are expected to remain popular with consumers, and supermarkets are
expected to respond to this demand by increasing the amount of ready-to-eat food items
offered at their fresh food departments, delis, bakeries and home meal departments (United
States Department of Agriculture Foreign Agricultural Service Report, 2010). The
epidemiology of foodborne illnesses has changed over the last two decades, with a rise in
bacterial infections caused by emerging organisms as well as a considerable increase in the
incidence of illness from well-recognised pathogens such as Salmonella (Forsythe & Hayes,
2002). In addition, there are certain food safety issues specifically associated with ready-to-
eat foods (Marriot & Gravani, 2006). For instance, Listeria spp. can become a threat if food
is not prepared hygienically and kept at the sub-optimal temperature (World Health
Organisation, 2004). In recent years, incidences of enteric diseases associated with meat
consumption have risen. The emergence of several new foodborne diseases has focused
2
attention on the issue of food safety. The most commonly implicated foods in these disease
outbreaks have been meat and dairy products (Gibson & Rastall, 2005). The following
organisms, Staphylococcus aureus, Salmonella spp, Listeria spp and Escherichia coli, and
their connection to processing hygiene and food handling practices will be included in this
study as they are the most frequent causes of food poisoning in developing countries,
including South Africa (Marriott & Gravani, 2006). These bacteria are also included in
South African legislation (Republic of South Africa, 1972).
1.2 THE IMPORTANCE OF CLEANING AND SANITATION
The most important goals of cleaning are to reduce the initial number of microbes on any
surface and slow the rate of their growth. The microorganisms that remain after the cleaning
step are more susceptible to sanitisers because the organic matter which serves as a food
source has been removed. The use of sanitisers, without proper cleaning, is usually a waste
of money and time as they serve no purpose, as only the microorganisms in the top layer of
soil will be killed. Cleaning compounds allow water to efficiently penetrate, dislodge and
remove soil (Marriot & Gravani, 2006). A detergent solution that comes into contact with
soil will remove it by means of good wetting and penetrating properties, namely: solid and
dispersed soils and will be displaced from a given surface by saponifying the fat, peptizing
the proteins and dissolving the minerals; the soil will be dispersed in the cleaning solution
due to de-flocculation or emulsification; and the soil will be prevented from re-depositing on
the surface due to the good rinsing quality of the cleaning compounds used. Given the huge
variety of cleaning and sanitation programmes available and the manifold cleaning concepts
that exist, it is important to identify which cleaning programme is best suited to a particular
process. For instance, a complete food safety programme includes both cleaning and
sanitation. Although cleaning removes soils, after the cleaning operation has been
3
completed, equipment surfaces and the environment in which food is handled can still be
contaminated with microorganisms. If these microorganisms are not destroyed, the food
being produced may become contaminated. The result may be food spoilage and possibly
foodborne illnesses (Marriot & Gravani, 2006). An effective sanitation programme is
important for many reasons and the most important principle in sanitization and/or
disinfection is that a dirty surface cannot be sanitized. Before a cleaning chemical is
selected, five key factors need to be understood (Rowberry, 2010). Firstly, it is important to
know the nature of the soil that needs to be cleaned, as different soils require different
cleaning chemicals and different cleaning methods. Secondly, the role of water is important
(more than 90 % of the cleaning solution comprises water); therefore, it is necessary to
know about the specific attributes and impurities in the water that will be used. Thirdly, is
the consideration of the composition of the surface being cleaned. Knowing whether the
surface is made of stainless steel, aluminium, brass, copper, iron, tile or plastic is important,
as different materials interact with soil as well as with the cleaning chemicals in different
ways. Even the nature of the surface itself affects the efficacy of cleaning and one must
consider whether the surface is smooth, polished, rough, pitted or corroded (Cramer, 2006).
Fourthly, the method of application should be taken into account very carefully, as there are
a number of different ways to apply cleaning chemicals to the area being cleaned. Each
application method presents a different level of exposure for the employee. During manual
application, the employee has direct contact with the cleaning solution and when spraying or
using high pressure cleaning, the chemical becomes airborne, which is of concern as it could
affect the worker‘s health and safety. Cleaning chemicals can be applied to a surface as a
foam or as a viscous material, thereby limiting, but not obliterating employee contact with
the cleaning chemicals. For mechanical cleaning and cleaning in place (CIP), no direct
employee contact is expected. Fifthly, consideration of the cleaning regime should be
4
supplemented by consideration of the impact of such a regime on the environment, as all
cleaning solutions and soil eventually become part of the waste stream and need to be
properly treated. The effluent may be treated at a public or privately owned treatment plant;
in either case, there are certain restrictions on the quality or characteristics of a particular
waste stream. When these factors and how they interact are understood, the ‗right choice‘
can be made (Marriot & Gravani, 2006).
In food premises, stainless steel is the preferred material for food contact surfaces and 304
or 316 grade stainless steel is often specified. In addition to stainless steel, other ‗soft‘
metals may be used, the most common being aluminium. Non-metallic surfaces, such as
plastics that are used for cutting boards, are being used more widely, not only in equipment
but also in packaging materials. The kind of surface that will be cleaned also determines the
cleaning chemical that will be used as they need to be compatible.
There are three basic application methods commonly used in the food manufacturing
industry: manual cleaning, high-pressure spray cleaning and foam cleaning. With manual
cleaning, the employee has the greatest potential for physical contact and, as such, the pH of
the solution needs to be kept between pH 4 and pH 10.5. Manual cleaning is mainly
performed with a bucket, cloth, brush or broom and the work is, as implied, performed
manually. When using high-pressure spray cleaning, the potential hazard exists that
microbes will be distributed into the surrounding area due to the formation of aerosols.
High pressure (> 80 Bar) is applied to the work surfaces, whereby the pressure supplies the
cleaning action. Because of the risk of spreading microbes with high-pressure spray
cleaning, this type of cleaning is generally not recommended for the food industry. With
foam cleaning, on the other hand, there is potential for the detergent to make better contact
with the surfaces. However, if the equipment is not adjusted properly, atomization can
5
occur, which break the chemicals into small particles would be inhaled by the cleaners this
also applies to the organic matter which could then settle on already cleaned areas.
Chemicals are applied in a foam format and as long as there is foam on the working surface,
there is contact with the soil and the surface area will be cleaned as the foam bubbles burst
and release energy (Stanga, 2010).
1.3 THE PRACTICES OF FOOD HANDLERS RELATED TO THE
PROCESSING OF CONVENIENCE FOOD
Food handlers must have the skills and knowledge to handle food safely as they carry out
the preparation work. Only food service workers who are healthy and practise good
personal hygiene should be working in a ready-to-eat establishment. There are general food
hygiene and food safety procedures that should be followed to help reduce the risk of
contamination and mishandling at all levels of a food establishment. From the time the food
is delivered to the minute it is served to the customer, food safety should be the top priority.
Despite an increase in the number of food handlers receiving food hygiene training, a high
proportion of food poisoning outbreaks still occur as a result of poor food handling practices
(Jay, et al. 2005). Maintaining good levels of hygiene necessitates that certain basic
requirements must be followed by food handlers, such as washing and sanitising their of
before commencing work on the production line, after touching the hair or face, after
picking up scraps from the floor and after adjusting equipment or handling non-product
contact items. Employees must wear hairnets to ensure they do not shed hair in the product.
In some instances, the use of disposable gloves, aprons and arm guards after washing one‘s
hands and sanitising is also recommended to protect the end-product from contamination.
After the food handlers have put gloves on, they should ideally dip their hands in a sanitising
solution. Whenever food handlers work with rejected packages, they should wash, sanitize
6
and cover their hands with fresh disposable gloves and, once finished with the work, discard
the protective wear before they commence work on the production line again. All utensils
and equipment should be kept away from the production areas and unnecessary contact with
these should be avoided (Arduser & Brown, 2005).
1.4 LEGISLATION APPLICABLE TO CONVENIENCE FOOD IN SOUTH
AFRICA
Limited South African food legislation currently exists on specific food products. As such,
the concern about foodborne illnesses is continuously growing. Aside from the Total Plate
Count (TPC), no other guidelines or legislation exist in South Africa regarding acceptable
indicatory levels of organisms on surfaces used in food handling. From a human health
perspective, all foodstuffs manufactured, processed or sold in South Africa, as well as those
imported into South Africa, are governed by the Department of Health under the Foodstuffs,
Cosmetics and Disinfectants Act (Republic of South Africa, 1972). The Guidelines for
Environmental Health Officers (Republic of South Africa, 1977) is provided to assist in the
interpretation of microbiological analysis data for food. It sets out to explain to
environmental health practitioners the significant species or groups of microorganisms used
in microbiological standards and to guide their interpretation of microbiological analysis
data, especially in instances where no microbiological legislative standards exist (Republic
of South Africa, 1977). This legislation is based on the view that access to safe and
affordable food is a basic human right. Consuming food that carries potential risks can be
harmful to one‘s health and consumers are entitled to expect and deserve protection against
preventable risks associated with consuming food. These aspects are all addressed in the
Health Regulations (Regulation 918 of 1999) promulgated under the Health Act (Republic
of South Africa, 1999). The Act aims to provide measures that can be used to promote the
7
health of the inhabitants of South Africa; to provide for the rendering of health services; to
define the duties, power and responsibilities of certain authorities that render health services
in South Africa; and to provide for the coordination of such health services. Regulation 918
deals with the hygiene requirements for food premises as well as the requirements for
transporting food, both of which are deemed basic standards that a food manufacturing
facility must comply with (Republic of South Africa, 1977). The South African Bureau of
Standards (SABS, 2001) plays an integral part in the food chain, from primary production to
the final consumer, by setting out the necessary good practices to ensure that food is handled
in such a way that the safety of the consumer is assured (SABS, 2001). All handled food is
expected to meet the minimum safety requirements expected by customers and regulatory
authorities. It is therefore essential that levels of undesirable substances in food meant for
human consumption be consistently below the levels stipulated as unsafe. Food handling
refers to the handling of food in its raw or unprocessed state as well as during production,
processing, packaging, transportation, delivery and display. The practices described in this
standard aim to assist food handling organisations in managing their operations in such a
way as to prevent or control the contamination of food, either through direct contamination
or as a result of cross-contamination (SABS, 2001). It further aims to assist food handling
organisations to initiate business operations that are based on a basic level of hygiene
(SABS, 2001).
1.5 RATIONALE
1.5.1 Aims of the study
The study aimed to compare the efficacy of low-pressure foam cleaning and conventional
cleaning in removing selected bacterial pathogens from surfaces associated with
convenience food. In the convenience food plants, the microbiological contamination on the
8
hands of food handlers, which indicates the level of hand washing efficacy in the
convenience food industry, were also be determined and a comparison of the food hygiene
knowledge and practices of these food handlers in the convenience food industry was
determined.
1.5.2 Research hypothesis
Cleaning methods have a significant influence on various convenience food quality and
safety indicators.
1.5.3 Null hypothesis
Cleaning methods do not have a significant influence on various convenience food quality
and safety indicators.
1.5.4 Data interpretation
The results were compared with the specifications advocated by the Department of Health
under the Foodstuffs, Cosmetics and Disinfectants Act (Republic of South Africa, 1972)
from a human health and safety control perspective (Republic of South Africa, 1972) as well
as the proper interpretation of microbiological analysis data related to food and the
specifications set out in the Guidelines for Environmental Health Officers in Regulation 918
(Republic of South Africa, 1977).
1.5.5 Relevance of study
The outcomes of this study should contribute to a better understanding of potential risks
associated with the processing of convenience food. This study should provide invaluable
information to the convenience food industry in order that it can optimise its processes and
personal/general hygiene practices.
9
1.6 REFERENCES
Arduser, L.& Brown, D.R. (2005). HACCP and sanitation in restaurants and food service
operations: A practical guide based on the FDA code. United States: Atlantic Publishing
Group.
Cramer, M.M. (2006). Food Plant Sanitation: Design, Maintenance and Good
Manufacturing Practices. Boca Raton, Florida: CRC Press Taylor & Francis Group.
Elliot, T.R. & Marth, E.H. (2007). Listeria, Listeriosis, and Food Safety. 3rd
edition.
United States: CRC Press Taylor & Francis Group.
Forsythe, S.J. & Hayes, P.R. (2002). Food Hygiene, Microbiology and HACCP. Pp. 24, 44.
Maryland: Aspen Publishers.
Gibson, G.R. & Rastall, R.A. (2005). Gastrointestinal infections and the protective role of
probiotics and prebiotics. IFIS Publishing,Shinfield.
Jay, J.M., Loessner, M.J. & Golden, D.A. (2005). Modern Food Microbiology. 7th edition.
Pp. 312-315, 507, 527,United States: Springer.
Marriott, N.G. & Gravani, R.B. (2006). Principles of Food Sanitation. 5th
edition. Pp. 10,
190. United States: Springer.
Republic of South Africa. (1972). Foodstuffs, Cosmetics and Disinfectants Act No. 54 of
1972. Pretoria: Government Printer.
Republic of South Africa. (1997). Regulations R. 692 of 16 May 1997. Pretoria:
Government Printer.
Republic of South Africa. (1999). Regulation 918 of 1999: Health Regulations governing
10
general hygiene requirements for food premises and the transport of food, promulgated
under the Health Act No. 63 of 1977. Pretoria: Government Printer.
Rowberry, J. (15 December 2010). Personal communication. Ecolab.
South African Bureau of Standards. (2001). Code of Practice: Food Hygiene Management.
3rd
edition. SABS No. 049. Pretoria.
Stanga, M. (2010). Sanitation: Cleaning and disinfection in the food industry. Germany:
Wiley-VCH.
World Health Organisation. (2004). Microbiological risk assessment series 5: Risk
assessment of Listeria monocytogenes in ready-to-eat foods. Technical report edited by the
World Health Organisation and printed in Geneva.
11
The following chapter was submitted partially or in full for publication in the journal:
Journal of Food Safety, ISSN: 1746-4565.
2. CHAPTER 2:
LOW-PRESSURE FOAM CLEANING COMPARED TO CONVENTIONAL
CLEANING FOR REMOVAL OF BACTERIA FROM SURFACES
ASSOCIATED WITH CONVENIENCE FOOD
2.1 ABSTRACT
The microbial load of eight convenience food manufacturing plants was determined by
sampling stainless steel food contact surfaces after they had been cleaned and sanitised at
the end of a day‘s shift. Samples were analysed for Total Plate Count (TPC), Escherichia
coli, Salmonella species and Staphylococcus aureus and Listeria species. The results
showed that 59 % of the total areas sampled for TPC failed to comply with the legal
requirements for surfaces of the South African Health Act (< 100 cfu.cm-2
). S. aureus and
Salmonella were not detected, but Listeria was detected in 23 % and E. coli in 1.3 % of the
samples, respectively. Fifty percent of the plants applied conventional cleaning methods for
cleaning and sanitation and 50 % used the low-pressure foam (LPF) method. The bacterial
counts after each cleaning method were statistically compared and a statistically significant
difference (P ≤ 0.05) was found between the TPC means of the cleaning methods. No
statistically significant difference (P > 0.05) was found in terms of the Listeria species
present after both cleaning processes. The LPF method proved to be the superior cleaning
option for lowering TPC counts. However, the results of this study emphasise that
production workers need to understand the correct application of chemicals as well as
receive intensive training in terms of proper chemical use.
12
2.2 INTRODUCTION
Public health concerned with food safety and food poisoning emerged in Britain in the
1880s, following the first indication that acute gastric illness was caused by a specific
organism (Morabia & Hardy, 2005).
The word ‗sanitation‘ is derived from the Latin word ‗sanitas‘, which refers to health. In the
food industry, this means the application of a regime to provide safe, wholesome food
processed in a clean environment by healthy workers who pose a limited health threat to the
end-consumer. As a result of the continuously fluctuating South African economy and the
ever-increasing cost of living, more people are now working than ever before in order to
sustain the average household income. The South African food industry is changing rapidly
and ready-to-eat products (convenience foods) internationally are becoming more popular
(Guillermo, 2006). According to Brand (2008): ―It was confirmed that there is a significant
growth in the convenience food market.‖
The need to assess the safety of food is increasingly being recognised (Mattick et al. 2003).
The attitude and/or knowledge required to practice effective hygiene control is lacking in
some food businesses. The bacteria responsible for food poisoning can proliferate quickly
in food, especially in warm and moist conditions. A single bacterial cell on an item of food
left out of the fridge overnight could produce millions of bacteria by the morning –
sufficient to cause foodborne illness (Prescott, Harley & Klein, 1996).
A recent study conducted in restaurants determined the incidence of a number of significant
foodborne pathogens and the general hygiene status, as estimated by TPCs and total
coliform counts (TCCs), on the interior surfaces of domestic refrigerators (Jackson et al.
2007). Some of the isolated species were found to survive and grow while refrigerated or
under mild temperature abuse conditions. Such pathogens (pschycrophiles) may transfer to
13
food in domestic fridges and multiply until they reach clinically significant numbers (Hayes
& Forsythe, 1989). These risks are of particular concerns in relation to ‗ready-to-eat‘ foods,
which will not receive any further processing before consumption (Jackson et al. 2007). A
study by Chao et al. (2006) revealed that counts of Listeria were 13.4 % higher on
delicatessen foods than on cooked foods tested during their study. Moreover, non-spore-
forming bacteria might be able to withstand dry conditions on surfaces for an extensive
period (Kusumaningrum, et al. 2003). Surveillance of bacteria has also become increasingly
important due to the increase in international food trade (Mayes & Mortimore, 2001). In
addition, microbiological hazards could stem from the introduction of new techniques for
mass production as well as the rapidly growing, widespread distribution of foodstuffs
(American Institute of Baking, 2002).
Organisms such as Total Aerobic Mesophiles, E. coli, S. aureus, Listeria species and
Salmonella species normally isolated from meat, dairy and vegetable products have been
universally utilised as indicators to determine the level of contamination on contact surfaces
after they have been cleaned and sanitised (Beckwith, 2008). The South African legal limit
for TPC on food contact surfaces is < 100 cfu.cm-2
(Republic of South Africa, 1999).
However, current legislation does not make provision for maximum counts related to E. coli,
S. aureus, Listeria species or Salmonella species on food contact surfaces (Republic of
South Africa, 1977).
2.3 A SYNOPSIS OF SURFACE-RELATED BACTERIA
E.coli is not considered a serious foodborne hazard in countries with high sanitary standards
and practices. Water contaminated with human sewage may lead to contamination of foods,
as can handling by infected food handlers. These organisms are infrequently isolated from
products (Jay, Loessner & Golden, 2005).
14
S. aureus food poisoning usually occurs rapidly and is in many cases acute, depending on
the individual‘s susceptibility to the toxin produced by this microbe, the amount of
contaminated food eaten, the amount of toxin in the food ingested and the general health of
the victim. Staphylococci exist in air, dust, sewage, water, milk and food or on food
equipment, environmental surfaces, humans and animals. Humans and animals are the
primary reservoirs of Staphylococci (Jay, Loessner & Golden, 2005), which are present in
the nasal passages and throats and on the hair and skin of over 50 % of healthy individuals.
Although food handlers are usually the main source of food contamination in food poisoning
outbreaks, equipment and environmental surfaces can also be sources of contamination with
S. aureus (Jay, Loessner & Golden, 2005).
Listeria species are of great concern to retailers in South Africa, especially Listeria
monocytogenes. The presence of this organism immediately is a reason for concern and the
retailer‘s procurement divisions will act strongly against any supplier who supplies products
that indicate the presence of Listeria species (Augustin, 2003), (Loken, 1995). L.
monocytogenes is a foodborne pathogen that causes listeriosis, which can be life threatening
and causes septicaemia, meningitis and even stillbirth in babies in high-risk populations
(Kornacki & Gurtler, 2007). Factory environments are not sterile and L. monocytogenes can
be found anywhere in the natural environment (Food Safety and Inspection Service, 2004).
This organism is easily introduced into food production facilities and also has the properties
needed to survive refrigerated temperatures and resist freezing (Lou & Yousef, 1997),
(Hemminger, 1999). Based on recent estimates from the Centres for Disease Control and
Prevention of the United States, the annual incidence of death caused by listeriosis is about
eight times greater than the mortality due to E. coli O157:H7 infections (Mead et al. 1999).
15
Salmonella food poisoning appears to be rising in the United States as well as in other
industrialised nations (Arduser & Brown, 2005). Salmonella enteritidis isolations from
humans have risen dramatically in the past decade, particularly in the Northeast USA
(sixfold or more), and the increase in human infections is spreading south and west, with
sporadic outbreaks occurring in other regions (Centres for Disease Control and Prevention,
1995). Salmonella live in the intestinal tracts of humans and other animals, including birds,
and in any raw food of animal origin, such as meat, poultry, milk and dairy products, eggs,
seafood and on some fruits and vegetables (Jay, Loessner & Golden, 2005).
The aim of this study was to identify whether selected organisms were present on sampled
food contact surfaces from eight convenience food plants in Gauteng, to relate the bacterial
count to the legal limit and to compare and evaluate the cleaning methods used with such
food contact surfaces (Verran, Boyd, Hall & West, 2001).
2.4 MATERIALS AND METHODS
2.4.1 Sampling protocol
This study was conducted amongst a sample of convenience food manufacturers supplying
convenience food products (ready-to-eat foods) during lunch hours to retail outlets in the
Gauteng area. This sample amounts to 20 % of the medium to large manufacturing plants
that supply the retail industry in the region. These eight outlets were chosen because they
mainly focus on preparing ready-to-eat lunch meals. Examples of foods manufactured
included ready-to-eat salads, sandwiches, fruit salads, filled pancakes or omelettes and
cocktail burgers. The management staff at each of the manufacturing plants sampled
granted permission to conduct the survey and subsequent interviews.
16
None of the premises were Hazard Analysis Critical Control Point (HACCP) certified. The
various food manufacturers used different chemical suppliers and the chemical companies
had different levels of cleaning technology; therefore, different levels of cleaning methods
were applied. Fifty percent of the outlets used traditional methods such as manual cleaning
(brush and bucket) and were supplied by local chemical manufacturers. International
companies supplied the remainder of the plants and they used more modern technologies
(for instance, low-pressure foam cleaning systems). Stainless steel food contact surfaces at
the manufacturing plants were sampled by means of swabs after they had been cleaned and
sanitised at the end of each day‘s shift (SANS, 2001). The samples were collected in
accordance with local health legislation (Republic of South Africa, 1999). To ensure that
the usual level of cleaning applied to contact surfaces occurred in all of the manufacturing
plants, workers were not informed of the planned sample collection. The sampling was
performed on days that required no overtime work, as overtime would potentially decrease
the time allotted for cleaning the contact surfaces. Thus, adequate time was available for
cleaning and sanitising of all contact surfaces. All samples were analysed on the same day.
A total of 477 microbiological samples were collected (205 samples were taken for the TPC
tests, 79 samples to determine the presence of E. coli, 27 samples to test for Salmonella
species and 27 samples to test for S. aureus and 139 samples to test for the presence of
Listeria species). Table 2.1 illustrates the findings. The samples were collected according
to the SABS swab technique method (South African Bureau of Standards: 1975) and all
analyses were performed at least twice.
17
Table 2.1: Total samples collected from convenience food contact surfaces at eight
food manufacturing plants.
1 ISO Method 4833 (International Organisation for Standardization, 2003)
2 Method SWJM 42 (Swift Micro Laboratories)
3
ISO method 11290-1 (International Organisation for Standardization, 1996)
4
ISO method 6888-1 (International Organisation for Standardization, 1999)
5
ISO method 16649-2 (International Organisation for Standardization, 2001)
Food Manufacturing
Plants
1TPC
2Salmonella
species
3Listeria
species
4Staphylococcus
aureus
5Escherichia
coli
Total/
plant
1 25 3 17 3 10 58
2 41 5 27 5 13 91
3 21 3 14 3 8 49
4 30 4 20 4 12 70
5 14 3 10 3 7 37
6 23 3 16 3 9 54
7 32 4 21 4 11 72
8 19 2 14 2 9 46
Total 205 27 139 27 79 477
18
2.5 MICROBIOLOGICAL ANALYSIS
The TPC samples were analysed using the conventional pour plate technique specified in
ISO Method 4833 (International Organisation for Standardization, 2003), whereas E. coli
analysis was performed by using solid growth media, as stipulated in ISO Method 16649-2
(International Organisation for Standardization, 2001). S. aureus was analysed using a
spread plate technique on Baird-Parker agar medium i.e. a pre-determined volume of the test
sample suspension spread onto the surface of a dried pre-poured BPA plate. No coagulase-
positive S. aureus growth was detected in the samples analysed using ISO Method 6888-1
(International Organisation for Standardization, 1999). Listeria species were analysed using
the conventional technique described in ISO 11290-1 (International Organisation for
Standardization, 1996).
Salmonella species were analysed using Malthus‘s methodology. The samples were
enriched using a non-selective enrichment broth and incubated at 35-37°C for 16-18 hours.
Presumptive positive colonies were confirmed using a Salmonella latex kit (SWJM 42)
(Swift Micro Laboratories).
2.6 DATA ANALYSIS
The results were analysed in collaboration with the Cape Peninsula University of
Technology‘s Corrie Uys, Statistician, Centres for Postgraduate Studies, and they are
presented in tables and graphs, using frequencies and percentages.
19
RESULTS AND DISCUSSION
2.6.1 Microbiological results for convenience food contact surfaces
2.6.1.1 Total Plate Count
The sample size (205 samples) proved to be 95 % accurate as a representative sample of the
population when using the Confidence and Error method with a tolerance of 5 %
(Krishnamurty, Kasovia-Schmitt & Ostroff, 1995). According to Figure 2.1, the highest
TPC found was 2.07 x 105
cfu.cm-2
(Plant 1) and the lowest had no detectable growth (0
cfu.cm-2
). Although all plants sampled had areas where there was no bacterial growth, the
legal limit of < 100 cfu.cm-2
with respect to the average TPC was exceeded without
exception (see Figure 2.1). Figure 2.1 furthermore shows the normal data distribution or
standard deviation and the average bacterial count, which considerably exceeded the legal
limit. This may indicate insufficient cleaning and disinfection, as one would expect a
significantly reduced or zero TPC after these cleaning processes have been conducted.
Table 2.2 presents a summary of the total samples taken and shows the compliance with the
legal limit (< 100 cfu.cm-2
for TPC) (Republic of South Africa, 1999). Overall, 84 of the
205 TPC samples (41%) complied with the legal requirement, whereas 121 of the 205
samples (59%) did not comply. This is an indication of the shortcomings in the used
cleaning methods of the eight manufacturing plants that were included in this study (Keller
et al. 2002). All TPC samples were collected from convenience food contact surfaces after
they had been cleaned and disinfected.
20
Figure 2.1: A comparison between the average Total Plate Count versus the legal limit
of < 100 cfu.cm-2
across manufacturing plants.
27571.20
10108.54 7489.52
1855.67
6562.86
924.78
13990.31
1916.84
1
10
100
1000
10000
100000
1 2 3 4 5 6 7 8
Co
un
ts c
fu.c
m-2
Manufacturing plants
Average
Legallimit
21
Table 2.2: The distribution of organisms according to compliance/non-compliance
and occurrence.
Compliance Non-compliance
Test No. of samples
(n) Absent < 100 cfu.cm
-2 > 100 cfu.cm
-2 Present
TPC 205 - 84 121 N/O
Escherichia coli 80 79 N/O N/O 1
Staphylococcus
aureus
27 27 N/O N/O N/0
Salmonella
species 27 27 N/O N/O N/0
Listeria species 139 107 N/O N/O 32
N/O = NOT OBSERVED
22
2.6.1.2 Escherichia coli, Staphylococcus aureus, Salmonella species and Listeria
species
Table 2.2 presents a summary of the total samples taken and indicate the presence or
absence of pathogens detected on the samples. Only one positive E. coli sample was found
and there was no detectable growth for Salmonella species and S. aureus. However, Listeria
species appeared to be an serious problem, as 32 positive samples were found.
Listeria species can be introduced into food-processing environments through many routes
and may establish colonies on food-processing equipment. Many commonly used
disinfecting or sanitising agents, such as quaternary ammonium compounds, chlorine and
iodophors have been shown to be effective against Listeria species in suspension, but
organic material reduces the activity of disinfectants (Van de Weyer, Devleeschouwer &
Dony, 1993). Subsequently, food products may become contaminated during processing. L.
monocytogenes may grow in biofilms that protect them against environmental stress and can
be isolated from surfaces after they have been cleaned and disinfected. In addition, L.
monocytogenes can adhere to all of the materials commonly used in the food industry. In
many food-processing environments, the conditions favour attachment and biofilm
formation, i.e. flowing water, suitable attachment surfaces and ample nutrients supplied by
the environment (Blackman & Frank, 1996). Therefore, several challenges exist in
controlling the proliferation of L. monocytogenes, including their increased resistance to
sanitisers and their ability to grow at the low temperatures found in ready-to-eat processing
plants. Figure 2.2 shows the total samples analysed for the presence or absence of TPC, E.
coli, S. aureus, Salmonella species and Listeria species. One point three percent (1.3 %) of
the total E. coli samples analysed were similarly positive. Although S. aureus and
Salmonella species were absent on these surfaces, 23 % of all Listeria species samples
analysed tested positive for the presence of this organism (Figure 2.2). These pathogens
23
pose a considerable threat to the safety of convenience food consumers (Kornacki & Gurtler,
2007). The toxin produced by S. aureus bacteria, which is called enterotoxin causes the
illness staphylococcal intoxication, which in turn leads to gastroenteritis or inflammation of
the intestinal tract lining. Hospitalization may be necessary for dehydration, but recovery is
usually within two days (Foodhandler, 2008). Although there are limited specifications
available on bacteria in food in South Africa, the norm is that all pathogens should be absent
(Republic of South Africa, 1997). Listeria species are very common and can be found
almost anywhere in the environment. As such, with food processing and manufacturing,
there is the potential to introduce the organism continuously (Donnelly, 2002). The
challenge is to direct efforts to prevent the growth and establishment of Listeria within the
plant through having appropriate controls such as sanitation, proper manufacturing practices
and employee training (Gilbert et al. 2000). E. coli was found on one sample in Plant 1
only, whereas the most positive Listeria samples were found in Plant 1 and Plant 7. Plant 1
also showed the highest average bacterial count, followed by Plant 7. It appears that the
overall hygiene standard of the plant influences the presence of Listeria.
24
Figure 2.2: Total samples analysed for the presence or absence of Total Plate Counts,
Escherichia coli, Staphylococcus aureus, Salmonella species and Listeria
species that were collected from convenience food contact surfaces in
eight food manufacturing plants.
18.2
98.7 100 100
77
81.8
1.3
23
0
10
20
30
40
50
60
70
80
90
100
Per
cen
tage
(%
)
Present
Absent
Total Plate Count Escherichia coli Staphylococcus aureus Salmonella sp. Listeria sp.
Microorganisms
25
2.6.1.3 Statistical comparisons of cleaning methods
Statistical analyses were used to determine which cleaning method (conventional cleaning
methods or low-pressure foam cleaning) is the better method to apply in the convenience
food industry. In order the conclusively demonstrate the efficacies of the cleaning methods,
SABS 1853 approved sanitisers that kill 99.9% of micro-organisms were used in 7 out of the
8 plants. The expected outcome was that all samples should be close to zero or at least be
compliant with the legal requirements of < 100 cfu.cm-2
. The samples were taken from
identical surfaces to ensure uniform results. The results indicated that the LPF system is
more effective, as proved by the lower mean of the TPC found on convenience food contact
surfaces cleaned with this method (Table 2.3). A statistical significant difference was found
in the TPC means of the cleaning methods (P ≤ 0.05; Table 2.3). The LPF method
consistently proved to be the better cleaning option for reducing TPCs. The presence of
Listeria species on convenience food contact surfaces was statistically evaluated but no
statistical significance was found between the cleaning methods used (P = 0.812)
(Jankowicz, 2002).
26
Table 2.3: Statistical significance between conventional cleaning and low-pressure
foam cleaning methods used on convenience food contact surfaces at eight
food manufacturing plants in terms of Total Plate Count.
Plants N = 205
Mean
TPC
Median
TPC
Standard
deviation
*P-value
cleaning
methods
Conventional
method 1, 2, 3, 7 119 14358.82 1240.00 33560.897
LPF method 4, 5, 6, 8 86 2386.51 35.00 7201.980
P ≤ 0.05
*P-values were calculated between the cleaning methods.
27
2.7 CONCLUSION
The results highlighted the presence of high counts of bacteria, including one pathogen in
particular (Listeria) that was detected on the sanitised or disinfected convenience food
contact surfaces. Fifty-nine percent (59 %) of the TPC samples analysed exceeded the legal
specification (< 100 cfu.cm-2
for food contact surfaces) when measured against the
requirements of the Health Act (Republic of South Africa, 1999). It is alarming that these
plants use reputable chemical suppliers‘ approved products but they still exhibit a pathogen
problem as well as generally high bacterial counts on contact surfaces. The majority of
positive samples for Listeria and TPC were found in Plants 1 and 7, with Plant 1 also having
one positive E. coli sample. Both of these plants made use of the conventional cleaning
method.
The LPF method was found to be significantly better (P ≤ 0.05) than the conventional
cleaning method in the manufacturing plants utilising these methods, respectively. The
results of this study may also raise questions as to whether workers or cleaners have
sufficient knowledge and/or insufficient training on how to apply the chemicals correctly to
achieve the desired results. It is therefore recommended that the management of the various
plants investigate the possibility of providing intensive training to the production workers
(including those acting as cleaners during their production shifts) and general cleaners. This
study has further highlighted the fact that pathogens continue to flourish on various surfaces,
including dry stainless steel, and present a contamination hazard for a considerable period,
depending on the contamination level and type of pathogen (Kusumaningrum et al. 2003).
28
2.8 REFERENCES
American Institute of Baking (AIB). (2002). AIB Consolidated Standards for Food Contact
Packaging Manufacturing Facilities.
American Meat Institute‘s Fact sheet on microbiological testing. (2004). Food Safety and
Inspection Service, Assessing the Effectiveness of the ―Listeria monocytogenes‖ Interim
Final Rule Report, Washington DC. Available from http://www.meatsafety.org (Accessed
30 November 2009).
Augustin, J-C. (2003). Evaluation of the sensitivity of microbiological criteria for Listeria
monocytogenes in detecting unsafe food according to the prevalence of the pathogen and the
shelf-life of the food. Food Microbiology, December 2003, 20(6): 681-689.
Arduser, L. & Brown, R.B. (2005). HACCP & Sanitation in Restaurants and Food Service
Operations: A Practical Guide Based on the FDA Food Code. p. 34. Florida: Atlantic
Publishing Group.
Beckwith, T (2008) Clean it or recall it, food plant sanitation manual, p. 1. Bloomington,
Indiana.
Blackman, I.C. & Frank, J.F. (1996). Growth of Listeria monocytogenes as a biofilm on
various food-processing surfaces. Journal of Food Protection, 59: 827-831.
Brand, J. (3 March 2008). Personal communication from Shoprite/Checkers.
Centers for Disease Control and Prevention. (1995). Morbidity and Mortality Weekly
Report, 16/12/1995, 44(49): 1253-1276. Available from
http://www.cdc.gov/mmwr/index2005.htm.
29
Centers for Disease Control and Prevention. (1996). Morbidity and Mortality Weekly
Report, 25/10/1996, 45(42): 901-936. Available from
http://www.cdc.gov/mmwr/preview/index96.html.
Chao, G., Deng, Y., Zhou, X., Xu, Q., Qian, X., Zhou, L., Zhu, Binyang, Z. (2006).
Prevalence of Listeria monocytogenes in delicatessen food products in China. Food
Control, 17(12): 971-974.
Clive, D. (2002). Foodborne Diseases. 2nd
edition. Toronto: Academic Press.
Donnelly, W.C. (2002). Editorial: Dispelling Myths about Environmental Listeria Control
Using Rapid, Cost-Effective Methods.
Elliot, T.R. & Marth, E.H. (2007). Listeria, Listeriosis, and Food Safety. 3rd edition.
United States: CRC Press Taylor & Francis Group.
Garbutt, J.H. & Garbutt, J. (1997). Essentials of Food Microbiology. London: Hodder
Arnold.
Gough, N.L. & Dodd, C.E.R. (1998). The survival and disinfection of Salmonella
typhimurium on chopping board surfaces of wood and plastic. Food Control, 9(6): 363-368.
Gounadaki, A.S., Skandamis, P.N., Drosinos, E.H. & Nychas, G-J.E. (2008). Microbial
ecology of food contact surfaces and products of small-scale facilities producing traditional
sausages. Food Microbiology Journal, 205: 313-323.
Gilbert, R.J., de Louvois, J., Donovan, T., Little, C., Nye, K., Ribeiro, C.D., Richards, J.,
Roberts, D., Bolton, F.J. (2000). Guidelines for the microbiological quality of some ready-
to-eat foods sampled at the point of sale. Communicable Disease and Public Health, 3(3).
30
Guillermo, E. (2006). Principles of Cleaning and Sanitation in the Food and Beverage
Industry. Nebraska: iUniverse.
Hayes, P.R. & Forsythe, S.J. (1989). Food Hygiene Microbiology and HACCP. 3rd
edition.
United States: Kluwer Academic/Plenum Publishers.
Hemminger, J.M. (1999). Food Safety: A Guide to What you Really Need to Know. Iowa:
Iowa State University Press.
International Organisation for Standardization. (1996). ISO 11290-1: 1996 Microbiology of
food and animal feeding stuffs -- Horizontal method for the detection and enumeration of
Listeria monocytogenes -- Part 1: Detection method.
International Organisation for Standardization. (1999). ISO 6888-1:1999 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of coagulase-
positive staphylococci (Staphylococcus aureus and other species) -- Part 1: Technique using
Baird-Parker agar medium.
International Organisation for Standardization. (2001). ISO 16649-2:2001 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of beta-
glucuronidase-positive Escherichia coli -- Part 2: Colony-count technique at 44 degrees C
using 5-bromo-4-chloro-3-indolyl beta-D-glucuronide.
International Organisation for Standardization. (2003). ISO 4833:2003 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of microorganisms
-- Colony-count technique at 30 degrees C.
Jackson, V., Blair, I.S., McDowell, D.A., Kennedy, J. & Bolton, D.J. (2007). The incidence
of significant foodborne pathogens in domestic refrigerators. Food Control, 18(4): 346-351.
31
Jankowicz, A.D. (2002). Business Research Projects. 3rd
edition. London: Thomson
Learning.
Jay, J.M., Loessner, M.J. & Golden, D.A. (2005). Modern Food Microbiology. 7th
edition.
United States: Springer.
Keller, S.E., Merker, R.I., Taylor, K.T. Tan, H.L., Melvin, C.D., Christel, S.T. & Miller,
A.J. (2002). Efficacy of Sanitation and Cleaning Methods in a Small Apple Cider Mill.
Journal of Food Protection, 65(6): 911-917.
Kornacki, J.L. & Gurtler, J.B. (2007). Incidence and control of Listeria monocytogenes in
food processing facilities. Chapter 17. Boca Raton, Florida: CRC Press Taylor & Francis
Group.
Krishnamurty, G.B., Kasovia-Schmitt, P. & Ostroff, D.J. (1995). Statistics: An interactive
text for the health and life sciences. London: Jones & Bartlett Publishers.
Kusumaningrum, H.D., Riboldi, G., Hazelger, W.C. & Beumer, R.R. (2003). Survival of
foodborne pathogens on stainless steel surfaces and cross-contamination to foods.
International Journal of Food Microbiology, 85(3): 227-236.
Loken, J.K. (1995). The HACCP Food Safety Manual. New York: John Wiley & Sons Inc.
Lou, Y. & Yousef, A.E. (1997). Adaptation to sub-lethal environmental stresses protects
Listeria monocytogenes against lethal preservation factors. Applied and Environmental.
Microbiology, 63(4): 1252-1255.
Marriott, N.G. & Gravani, R.B. (2006). Principles of Food Sanitation. 5th
edition. United
States: Springer. pp. 10, 190.
32
Mattick, K., Durham, K., Domingue, G., Jorgensen, F., Sen, M., Schaffner, D.W. &
Humphrey, T. (2003). The survival of foodborne pathogens during domestic washing-up
and subsequent transfer onto washing-up sponges, kitchen surfaces and food. International
Journal of Food Microbiology, 85(3): 213-226.
Mayes, T. & Mortimore, S. (2001). Making the most of HACCP. Cambridge: Woodhead
Publishing Limited.
Mead, P.S., Slutsker, L., Dietz, V., McCaig, L.F., Bresee, J.S., Shapiro, C., Griffin, P.M. &
Tauxe, R.V. (1999). Food related illness and death in the United States. Emerging
Infectious Diseases, 5: 607-625.
Morabia, A. & Hardy, A. (2005). The pioneering use of a questionnaire to investigate a
foodborne disease outbreak in early 20th Century Britain. Journal of Epidemiology &
Community Health, 59: 94-99.
Prescott, L.M., Harley, J.P. & Klein, D.A. (1996). Microbiology. 3rd
edition. . P. 886
Dubuque, Iowa: Wm. C. Brown Publishers.
Republic of South Africa. (1977). Health Act No. 63 of 1977. Pretoria: Government Printer.
Republic of South Africa. (1997). Regulations Governing Microbiological Standards for
Foodstuffs and Related Matters (R. 692 of 16 May 1997), Promulgated Under the
Foodstuffs, Cosmetics and Disinfectants Act 54 of 1972. Pretoria: Government Printer.
Republic of South Africa. (1999). Regulation 918 of 1999: Health Regulations Governing
General Hygiene Requirements for Food Premises and the Transport of Food, Promulgated
Under the Health Act No. 63 of 1977. Pretoria: Government Printer.
South African National Standards (2001). 1853: Disinfectants for use in the food industry.
33
South African Bureau of Standards. (1975). Swab technique method 762.
Van De Weyer, A., Devleeschouwer, M-J. & Dony, J. (1993). Bactericidal activity of
disinfectants on Listeria. Journal of Applied Bacteriology, 74: 480-483.
Verran, J., Boyd, R.D., Hall, K. & West, R.H. (2001). Microbiological and Chemical
Analyses of Stainless Steel and Ceramics Subjected to Repeated Soiling and Cleaning
Treatments. Journal of Food Protection, 64(9): 1377-1387.
Swift Micro Laboratories Quality Manual – Method SWJM 42.
34
The following chapter will be submitted partially or in full for publication in the
journal: Journal of Food Control, ISSN: 0956-7135.
3. CHAPTER 3:
MICROBIOLOGICAL CONTAMINATION ON THE HANDS OF FOOD
HANDLERS AS AN INDICATOR OF HAND WASHING EFFICACY IN THE
CONVENIENCE FOOD INDUSTRY IN SOUTH AFRICA
3.1 ABSTRACT
The study aimed to evaluate the efficacy of hand washing practices and sanitation before
commencing work. Samples were collected from the washed and sanitised dominant hands
of food handlers in the convenience food industry in Gauteng and were analysed for the
presence of Total Plate Count (TPC), Staphylococcus aureus and Escherichia coli. A total
of 230 samples were collected, involving 100 % of the food handlers in selected
convenience food outlets. The highest bacterial count from the hand samples was 7.4 x 103
cfu.cm-2
and the lowest showed no detectable growth. Sixty percent of the TPC analysed
exceeded the legal limit for food surfaces or hands of < 100 cfu.cm-2
and only 18 % of the
food handlers had no bacteria detectable on their hands. One sample tested positive for E.
coli, which is generally viewed as an indication of faecal contamination. S. aureus could not
be detected on the hands of any of the food handlers. The results of this study indicated that
hand hygiene in convenience food plants is unsatisfactory and underlined the importance of
further training to improve food handlers‘ knowledge of good hand washing practices.
35
3.2 INTRODUCTION
The hands of ready-to-eat food service employees have been shown to be vectors in the
spread of foodborne disease, mainly because of poor personal hygiene. Howes, McEwen,
Griffiths and Harris (1996) state that improper food handler practices contributed to
approximately 97 % of foodborne illnesses in food service establishments and homes. It is
of utmost importance that high standards of sanitation, cleanliness and good housekeeping
be maintained at all times and any laxness in this regard may result in a serious epidemic or
infection (Marriott, 1999). Employees should be trained on how to handle food as well as
on sanitation and hand washing techniques, as bacteria from cuts, infections, boils or other
communicable diseases may cause food poisoning (Richard, 2008). Statistical evidence
indicates that food poisoning caused by the catering industry is 70 % higher than that caused
by any other sector (Wilson et al. 1997). From this brief description, it should be evident
that people involved with every stage of food production, from farm to fork must take
responsibility to prevent infections and destroy pathogens (Nestle, 2003).
Hand washing is a fundamental precautionary measure to protect against the spread of
disease and is one of the primary practices to reduce the transfer of bacteria, whether from
person to person, or from person to food contact surfaces (Brodie, 1965). The main reason
for limiting contact between ready-to-eat foods and people‘s hands is to prevent the transfer
of viruses and bacteria that are already present in human bodies (Lues & Van Tonder, 2007).
Furthermore, it was established that a food worker‘s unwashed hands can transmit
pathogens, especially faecal pathogens, to food products after he or she uses the toilets.
Investigations of foodborne illness outbreaks have shown that poor personal hygiene,
primarily ineffective hand washing, is an important contributor to foodborne illness, second
only to inadequate temperature controls of food (Scarborough, 2002). When consumed in
36
food, these pathogens can cause illness and disease (Eley, 1997). In 1986, the Centres for
Disease Control and Prevention (CDC) Guidelines for Hand Washing and Hospital
Environmental Control recommended the following procedure to prevent transmission of
infectious diseases in hospitals: ―For routine hand washing, a vigorous rubbing together of
all surfaces of lathered hands for at least 10 seconds, followed by thorough rinsing under a
stream of water (FDA, 1997). If plain soap / bar soap is used, it should be kept on racks that
allow drainage of water.‖ If liquid soap is used, the soap container should be replaced when
it is empty because of the possible introduction and growth of pathogens in the liquid soap
during refilling (Snyder, 1999). These recommendations are designed to prevent the transfer
of infectious organisms from one person to another in healthcare settings (Sehulster &
Chinn, 2003) (Lee, Long & Phillip, 2004). The effects of hand washing in the prevention of
disease transmission from person to food and food to person are undeniable; however, the
goal of effective compliance remains unmet (Le Texier, 2001).
According to Government Regulation 918 of 1999, promulgated under the Health Act, No.
63 of 1977 (Republic of South Africa, 1999), it is a requirement for food handlers to wash
their hands with soap and hot and/or cold water before handling any food product or
container or working in a food facility. This regulation further stipulates that a maximum of
100 viable organisms are allowed per cm2
after cleaning and sanitation of food contact
surfaces has occurred. For the purpose of this study, the same standard will be applied to
workers‘ hands, as they come into direct contact with the ready-to eat food produced.
Annexure B of the Guidelines for Environmental Health Officers on the Interpretation of
Microbiological Analysis Data of Food (2007) for South Africa does not make provision for
maximum counts related to E. coli and S. aureus on food contact surfaces or hands, but the
organisms must be absent in all food products.
37
This study was done to evaluate the efficacy of hand washing practices and sanitation
amongst food handlers before they commence working in convenience food plants in the
Gauteng Province of South Africa. The study should add to the existing body of knowledge
on hand washing and sanitation in the ready-to-eat food industry.
3.3 MATERIALS AND METHODS
3.3.1 Sampling protocol
A 20 % sample was randomly selected from 40 convenience food outlets in Gauteng, which
were selected because their predominant focus is on preparing ready-to-eat foods
(Krishnamurty, Kasovia-Schmitt & Ostroff, 1995). Workers‘ cleaned and disinfected
dominant hands, which are normally in direct contact with the food, were sampled after staff
passed through the hand washing area and before they commenced work, according to
SABS method 762 regarding the swab technique (1975). A total of 230 microbiological
samples were collected and analysed for the presence of TPC, S. aureus and E. coli (Table
3.1). One manufacturing plant per day was sampled and samples were transported to the
laboratory on ice and analysed on the same day as sampling occurred. A total of 88 samples
were collected for TPC analysis, 77 samples for the presence of E. coli and 65 samples to
test for S. aureus. In order to ensure the consistency of workers‘ normal practices in
washing and disinfection, they had no prior knowledge of the planned sampling runs. In
total, 100 % of the workers at the eight convenience food plants were sampled for the
microorganisms mentioned. Furthermore, the samplings were collected on working days
and adequate time was allowed for workers to clean and sanitize their hands. Results are the
means of duplicate analyses.
38
Table 3.1: Distribution of samples collected from hands.
Convenience
Food
Manufacturing
Plants
1Total Plate
Count
2Escherichia coli
3Staphylcoccus aureus
Total/
plant
1 9 9 9 27
2 12 11 10 33
3 11 8 8 27
4 13 12 11 36
5 9 7 6 22
6 14 12 9 35
7 10 9 5 24
8 10 9 7 26
Total 88 77 65 230
1 ISO method 4833 (International Organisation for Standardization, 2003)
2 ISO method 16649-2 (International Organisation for Standardization, 2001)
3 ISO method 6888-1 (International Organisation for Standardization, 1999)
39
3.3.2 Microbiological analysis
The TPC samples were analysed using the conventional pour plate technique in ISO Method
4833 (International Organisation for Standardization, 2003). E. coli analysis was performed
with three test methods, using both broth and solid growth media, as stipulated in ISO
Method 16649-2 (International Organisation for Standardization, 2001). S. aureus was
analysed using a spread plate technique on Baird-Parker agar medium i.e. a pre-determined
volume of test sample suspension spread onto the surface of a dried pre-poured BPA plate.
No coagulase positive S. aureus growth was detected in the samples analyzed using ISO
Method 6888-1.
Data analysis
The results were analysed in collaboration with the Cape Peninsula University of
Technology‘s Corrie Uys, Statistician, Centres for Postgraduate Studies, and they are
presented in tables and graphs, using frequencies and percentages.
RESULTS AND DISCUSSION
3.3.3 Microbiological results of convenience food worker’s hands
3.3.3.1 Total Plate Count
The highest bacterial count found from the hand samples was 7,4 x 103 cfu.cm
-2 (Plant 2)
and the lowest had no detectable growth (Figure 3.1). Although hands with a count of 0
cfu.cm-2
were found in all of the plants, the results indicated that all of the premises sampled
exceeded the legal limit of < 100 cfu.cm-2
when the average bacterial counts on hands were
compared.
40
The normal data distribution, standard deviation and average bacterial count considerably
exceeded the legal limit (Jankowicz, 2002). Except at plants 5 and 8, the average bacterial
count was higher than 103 cfu.cm
-2 and one premises (Plant 2) exceeded 10
4 cfu.cm
-2. The
primary action of hand washing is the mechanical removal of viable transient
microorganisms, whereas the primary action of antimicrobial soap includes both mechanical
removal and killing or inhibition of both transient and resident flora (Larson, 1989), (SABS,
2001). This is an indication of insufficient hand washing and sanitation, as one would
expect a significantly reduced bacterial count on the workers‘ hands after they have cleaned
and sanitised them (South African Bureau of Standards, 2001). Paulson (1992) & Raspor
(2008) reported the importance of management training of all employees in the use of
effective hand washing procedures, and that the safety of food chain supply can easily be
broken proper enforcement these procedures, is the only solution. Sixty percent of the TPC
samples analysed exceeded the legal limit (< 100 cfu.cm-2
) stipulated by the Health Act for
food contact surfaces (Republic of South Africa, 1999)(Figure 3.2).
41
Figure 3.1: Comparison between the standard deviation and the average Total Plate
Count versus the legal limit of < 100 cfu.cm-2
.
8126 12557
2055 1801
856
6135 6420
794
11634 21629
2988 3744
1878
15128 16024
2326
100 100 100 100 100 100 100 100
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
1.00E+05
1 2 3 4 5 6 7 8
Lo
g C
ou
nts
cfu
.cm
-2
Food Manufacturing Plants
Avg
StdDevLegallimit
42
Figure 3.2: Total samples analysed for the presence or absence of Total Plate Count,
Escherichia coli and Staphylococcus aureus that were collected from
workers‘ cleaned and sanitised dominant hand surfaces in eight
convenience food manufacturing plants.
40
99 100
60
1
0
10
20
30
40
50
60
70
80
90
100
Total Plate Count Escherichia coli Staphylococcus aureus
Per
cen
tage
(%
)
Groups of organisms
Present
Compliant
43
3.3.3.2 Escherichia coli
Only one sample (Plant 6) tested positive for E. coli in the hand samples analysed (Figure
3.2). As E. coli is found in the intestinal tract of both humans and animals, finding this
organism in ready-to-eat foods is generally viewed as an indication of faecal contamination.
Faecal contamination, in turn, indicates that other harmful organisms, whether they be
bacterial genera (Salmonella, Shigella, Campylobacter), viral (Hepatitis A, norovirus,
rotavirus) or helminthic or protozoal parasites (Taenia, Toxoplasma, Cryptosporidium,
Giardia), could be present (Jay, 1997). In addition, the test for generic E. coli may also
point to highly pathogenic strains of E. coli that have the ability to cause diarrhoea as well as
systemic disease, resulting in multi-organ failure and death (E. coli 0157:H7) (Sciencedaily,
2010). It is for these reasons that the confirmation of E. coli in ready-to-eat food is followed
by an automatic recommendation for a thorough review of the constituent ingredients, as
well as finished product re-testing and task-oriented training of those individuals involved in
the preparation of those specific ready-to-eat food items.
44
3.3.3.3 Staphylococcus aureus
Throughout the eight food premises, S. aureus could not be detected on the hands of food
handlers (Figure 3.2). S. aureus and coagulase-negative Staphylococci (CNS) inhabit the
human skin and mucous membranes, where they exist mostly as commensal flora (Nobel,
1992). Humans are the natural carriers of S. aureus and the organism can be found in a
healthy human population (Montville & Matthews, 2008). The onset of symptoms in
staphylococcal food poisoning is usually rapid and in many cases acute, depending on the
individual‘s susceptibility to the toxin, the amount of contaminated food eaten, the amount
of toxin in the food ingested and the general health of the victim. Staphylococci exist in air,
dust, sewage, water, milk and food or on food equipment, environmental surfaces, humans
and animals. Humans and animals are the primary reservoirs of Staphylococci (Montville &
Matthews, 2008). Table 3.2 represents a summary of the TPC samples collected and shows
the distribution of organism growth as well as the legal limit (100 cfu.cm-2
).
45
Table 3.2: The distribution of compliance in terms of Total Plate Count compared to
the legal limit.
Test No Growth > 0 - ≤ 10 cfu.cm-2
> 10 - ≤ 100 cfu.cm-2
> 100 cfu.cm-2
TPC 16 7 12 53
Comply = 40 % Not Comply = 60 %
46
3.4 CONCLUSION
It appears that the overall hand hygiene does not necessarily influence the presence of
indicator organisms. Plant 6 showed the fourth highest average bacterial count in the hand
samples and was the only plant with E. coli present. There are limited specifications
available for bacteria in food but the norm is that all pathogens and/or indicator organisms
should be absent (Guidelines for Environmental Health Officers on the Interpretation of
Microbiological Analysis Data of Food, 2007).
The microbiological quality of food can be improved, especially with regard to
contamination from bacteria on food handlers‘ hands. Nevertheless, the study revealed that
hand hygiene is unsatisfactory and it underlines the need to improve food handlers‘ hygiene
knowledge by focusing on hand washing practices. The hands examined using the TPC
revealed unacceptable contamination in 60 % of the samples, whereas 18 % had no bacterial
growth in terms of the species analysed. These findings indicate that sanitation protocols are
not being applied in such a way that they will ensure complete food safety in ready-to-eat
manufacturing plants. Furthermore, the microbiological levels on the hands sampled can be
used as an indicator to determine controls in future Hazard Analysis Critical Control Point
(HACCP) systems. Knowing about these problems is essential to improving the controls
systems in ready-to-eat food production establishments and for adjusting the existing staff
training programmes. Training the workers in basic hand washing principles is
recommended considered, as the overall results indicated that the hands of food handlers in
all eight ready-to-eat food manufacturing plants involved in this study exceeded the legal
requirements for food contact surfaces.
47
3.5 REFERENCES
Brodie, J. (1965). Hand hygiene. Scottish Medical Journal, 10(1): 115-125.
Department of Health. (2007). Guidelines for Environmental Health Officers on the
Interpretation of Microbiological Analysis Data of Food. Directorate Food Control (July
2007).
Eley, A. (1997). Escherichia coli 0157: An increasingly significant food-poisoning
pathogen. Journal of Nutrition & Food Science, 91(3): 96-100.
FDA. (1997). Food Code. U.S. Public Health Service, U.S. Dept. of Health and Human
Services. Food and Drug Administration Pub. No. PB97-141204. Washington, DC.
Howes, M., McEwen, S., Griffiths, M. & Harris, L. (1996). Food handler certification by
home study: Measuring changes in knowledge and behaviour. Dairy, Food and
Environmental Sanitation, 16: 737-744.
International Organisation for Standardization. (1999). ISO 6888-1:1999 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of coagulase-
positive staphylococci (Staphylococcus aureus and other species) -- Part 1: Technique using
Baird-Parker agar medium.
International Organisation for Standardization. (2001). ISO 16649-2:2001 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of beta-
glucuronidase-positive Escherichia coli -- Part 2: Colony-count technique at 44 degrees C
using 5-bromo-4-chloro-3-indolyl beta-D-glucuronide.
48
International Organisation for Standardization. (2003). ISO 4833:2003 Microbiology of
food and animal feeding stuffs -- Horizontal method for the enumeration of microorganisms
-- Colony-count technique at 30 degrees C.
Jankowicz, A.D. (2002). Business Research Projects. 3rd
edition. London: Thomson
Learning.
Jay, J.M. (1997). Modern Food Microbiology. 5th
edition. New York: Chapman & Hall.
pp. 17-19.
FoodHandler. (28 November 2008). Keep the Staph Out of Your Food. Available from
http://www.foodservice.com/articles/article.cfm?contentid=718&CTID=14 (Accessed 13
December 2009).
Krishnamurty, G.B., Kasovia-Schmitt, P. & Ostroff, D.J. (1995). Statistics: An interactive
text for the health and life sciences. London: Jones & Bartlett Publishers.
Larson, E. (1989). Hand washing: It‘s essential – even when you use gloves. American
Journal of Nursing, 89: 934-939.
Lee, A., Long, C. & Phillips, R. (2004). Hand hygiene: the efficacy of an alcohol-based
hand sanitizer vs. an antimicrobial soap and water. Journal of Dental Hygiene, No.4, 1
October 2004.
Le Texier, R. (2001). Preventing infection through hand washing. Infection Control Today.
Available from http://infectioncontroltoday.com/articles/071feat2.html (Accessed 19
October 2009).
49
Lues, J.F.R. & van Tonder, I. (2007). The occurrence of indicator bacteria on hands and
aprons of foodhandlers in the delicatessen sections of a retail group. Food Control, 18: 326-
332.
Marriott, N.G. (1999). Principles of Food Sanitation. 4th
edition. Gaithersburg, Maryland:
Aspen Publishers.
Montville, T.J. & Matthews, K.R. (2008). Food Microbiology: An Introduction. 2nd
edition.
Washington DC: ASM Press.
Nestle, M. (2003). Safe Food, Bacteria, Biotechnology and Bioterrorism. London:
University of California Press, Ltd.
Nobel, W.C. (1992). The Skin Microflora and Microbial Skin Disease. Cambridge:
Cambridge University Press.
Paulson, D.S. (1992). Evaluation of three hand wash modalities commonly employed in the
food processing industry. Dairy, Food and Environmental Sanitation, 12(10): 615-618.
Raspor, P. (2008). Total Food Chain Safety: How good practices can contribute. Trends in
Food Science & Technology, 19: 405-412.
Republic of South Africa. (1999). Regulation 918 of 1999: Health Regulations governing
general hygiene requirements for food premises and the transport of food, promulgated
under the Health Act No. 63 of 1977. Pretoria: Government Printer.
Richard, K. (2008). Hand-washing prevent food-borne illnesses
Food-borne illnesses kill about 5,000 people each year. Campus News
50
Science Daily, E. Coli 0157:H7 Present but Not Common in Wildlife of Nation's Salad Bowl
(5 May 2010).
South African Bureau of Standards. (2001). Disinfectant and Detergent-Disinfectants for
use in the Food Industry. SANS/SABS 1853.
Scarborough, M.F. (2002). Hand Washing in Georgia’s Public Schools – A Community
Needs Assessment and Intervention Study. Masters thesis. Atlanta, United States: Emory
University.
Sehulster, L. & Chinn, R.Y.W. (2003). Guidelines for Environmental Infection Control in
Health-Care Facilities: Recommendations of the CDC and Healthcare Infection Control
Practices Advisory Committee (HICPAC). Morbidity and Mortality Weekly Report, 52 (No.
RR-10): 1-42.
Snyder, O.P. (1999). A "Safe Hands" Hand Wash Program for Retail Food Operations.
Hospitality Institute of Technology and Management, Dairy Food Environ. Sanitation.
18(3): 149-162.
South African Bureau of Standards. (1975). Swab technique method 762, South African
Bureau of Standards, Pretoria.
Wilson, M.,Murray, A.E., Black, M.A., McDowell, D.A. (1997) The implementation of
Hazard Analysis and critical control points in hospital catering. Managing Service Quality
7(3): 150-156.
51
The following chapter will be submitted partially or in full for publication in the
journal: Journal of New Generation Sciences, ISSN: 1684-4998.
4. CHAPTER 4:
FOOD HYGIENE KNOWLEDGE AND PRACTICES OF FOOD HANDLERS
IN THE CONVENIENCE FOOD INDUSTRY IN THE GAUTENG PROVINCE,
SOUTH AFRICA
4.1 ABSTRACT
The purpose of this study was to present data on the food hygiene knowledge and practices
of food handlers and managers based on a representative sample from convenience food
outlets in the Gauteng area. Management as well as food handlers were interviewed by
means of a structured questionnaire. Interviews were conducted without prior
announcement and managers were interviewed prior to starting their shifts, followed by food
handlers, after they had passed through the change room and hand wash facilities. Although
the majority of food handlers adhered to basic hygiene principles, the results highlighted a
need for proper and continuous training in hygiene practices, not only for food handlers, but
also for management. Failure to wash hands after blowing noses and smoking were found to
be issues of concern. Food handlers failed to select the correct answer in 36.4 % and 30.7 %
of these cases, respectively. Some of the plants did not have an adequate supply of hot
water to use for cleaning. Only 34 % of respondents had received training from the
chemical suppliers on how to use their products. It is recommended from this study that all
food handlers should adhere to a formal cleaning schedule. Specific courses should be
planned for food workers as, currently, most training is done away from the workplace and
the workers might find it difficult to translate theory into practice. Although food safety
training programmes are essential, behavioural changes will not occur merely as a result of
having received training, thus should be further developed. In-house training explaining the
problems and solutions should be done and the food handlers should take ownership of the
problem.
52
4.2 INTRODUCTION
Accessing good quality food has been humankind‘s main endeavour from the earliest days
of existence and food safety remains a critical issue in the light of outbreaks of foodborne
illnesses that result in substantial cost to individuals, the food industry and the economy
(Kaferstein, Motarjemi & Bettcher, 1997). Some food is inherently contaminated with
microorganisms and food handlers must therefore be taught the significance of hygiene
knowledge and good practices and fully understand that they must ensure that
microorganisms do not spread to other items. Food handlers are responsible for proper
cooking, segregation and storage of food (Barrie, 1996). The safety of food is a basic
requirement of food quality. ―Food safety‖ implies an absence or acceptable and safe levels
of contaminants, adulterants, naturally occurring toxins or any other substance that may
make food injurious to health on an acute or chronic basis (McElhatton & Marshall, 2007).
Food handlers‘ errors have been responsible for most outbreaks of food poisoning (Clayton
et al. 2002). Despite an increase in the number of food handlers receiving food hygiene
training in recent years, a high proportion of food poisoning outbreaks still occur as a result
of poor food handling practices (Gomes-Neves et al. 2007). The kitchen staff and food
handlers of a restaurant, deli, cafeteria, meat market and bar are a common source of
bacteria and viral contamination in food, which can very readily cause consumers to become
ill (Doom, 2008). Hand washing is easy to perform and it is one of the most effective ways
to prevent the spread of many types of infections and illnesses in all settings – from the
home and workplace to childcare facilities and hospitals (Baş, Ersun & Kivanç, 2006).
When it comes to preventing and controlling the spread of microbes in food processing
operations, it is hard to overstate the importance of implementing and enforcing proper
employee hand washing regimes. Various studies indicate that poor hand washing habits by
food handlers and the contamination of food by animal faeces were among the prime
53
reasons that Americans get sick due to foodborne microbes (Centres for Disease Control and
Prevention, 2005). In cases where a foodborne agent was identified, norovirus was the most
common cause of illness (39 %), followed by Salmonella (27 %). The most common cause
of norovirus outbreaks can be attributed to infected food handlers who do not wash their
hands well after using the toilet (Centres for Disease Control and Prevention, 2008).
Salmonella outbreaks are most often caused when food is contaminated with animal faeces.
Salmonella contamination usually involves animal-related foods such as beef, poultry, milk
and eggs; however, vegetables and other foods can also be contaminated, according to the
Diagnosis and Management of Foodborne Illnesses data (Centres for Disease Control and
Prevention, 2004). Studies indicate that personnel in both the healthcare and food service
industries have poor hand washing habits. For instance, 60 % of the food service personnel
in one study did not wash their hands after using the toilet (Emery, 1990). This study
examined food handler‘s beliefs about food safety and determined food handler‘s self-
reported practices.
54
4.3 MATERIALS AND METHODS
Eight convenience food manufacturing plants were randomly selected for the purpose of
conducting interviews with food handlers who prepare ready-to-eat foods. Confidentiality
agreements were signed to ensure that the manufacturers remain anonymous.
4.3.1 Pilot study
The questionnaire was piloted in one outlet and involved eight food handlers and the
manager of the respective department. This outlet was not included in the final sample. The
purpose of the pilot study was to determine whether enough time would be available to
complete the questionnaires before production started, whether the information gathered
would provide enough evidence to draw conclusions, whether respondents generally
understood the questions correctly as well as to adjust the study if any minor difficulties
were experienced.
4.3.2 Sampling protocol
Interviews based on structured questions were completed by a target population (88) that
represented 100 % of the population of food handlers in each manufacturing department of
each plant, including the manager. All of the managers and food handlers were permanent
employees and had been with each respective manufacturing plant for more than 12 months.
The eight convenience food manufacturing plants were selected because they predominantly
supply ready-to-eat products to the bigger retailers and produce the biggest volumes of food.
These plants constitute about 20 % of the ready-to-eat food manufacturing plants in the
Gauteng region. The interviews were conducted on a one-on-one basis with the food
handlers before they commenced their shift, but after they had entered their working
environment. The interviews were done on an unannounced basis. The same interviewer
55
conducted all of the interviews to ensure consistency and the correct explanation of the
questions and interpretation of the answers.
4.3.3 Questionnaire design
A questionnaire was designed to determine three elements: a) the level of involvement of the
management in protecting the product integrity; b) whether a safe product reaches the
consumer; and c) whether food handlers pose a risk to the safety of the product (Appendix
A). It was stated at the outset of the interview that confidentiality would be protected and no
names would be recorded. The questionnaire was only available in English; however, all of
the food handlers indicated that they were comfortable to answer questions in English and
no translation was required. Out of a total of 46 questions, 21 questions targeted
management practices and 25 questions were aimed at the food handlers. The questions
aimed at the managers were related to food safety systems and prerequisite standards as well
as risk assessment within the plant and compliance with standards and/or legislation. The
remaining questions designed for the food handlers were strictly focused on their knowledge
of personal hygiene and cleaning and sanitation practices in their working environment. The
structured interview method allowed the interviewer to ask all of the respondents the same
questions in the same manner (Rogers, 2001).
4.3.4 During the interview
The interviews were conducted without prior announcement and care was taken not to
deviate from the questions listed in the questionnaire. Upon entering the various
manufacturing plants, the managers were interviewed prior to starting their respective shifts,
followed by the food handlers as they entered the respective facility after passing through
the change room and hand wash area. The purpose of the study was explained to them and
assurance was given about the confidentiality of their identities.
56
4.3.5 Data analysis
The data collected were analysed and statistically prepared for reporting. The results were
expressed in percentages and frequencies as well as indicated the response rate (n) for each
question.
4.4 RESULTS AND DISCUSSION
4.4.1 Level of management involvement
Management involvement is important, as it is necessary to manage plant hygiene practices
in a top-down manner. The eight selected plants were not Hazard Analysis Critical Control
Point (HACCP) certified but implemented control measures to improve their own hygiene
quality. Only 62.5 % of the plants performed regular testing of process water to determine
the quality of water used for processing, washing hands and work surfaces (Table 4.1). The
respondents reported performing risk assessments: 62.5 % identified critical areas; 50 %
reported that they verified the control measures for the critical areas, whereas 37.5 %
conducted validations of the critical process steps. Thirty-seven point five percent of the
respondents used an official food safety decision tree to determine the critical areas correctly
(Table 4.1). Richardson and Stevens (2003) conclude that management may represent a
contributing factor to poor microbiological quality and prioritizing improved training of
managers is more important than training the food handlers to ensure the good hygiene of
the premises. By setting an example, the senior management can further enhance the level
of training of food handlers (Sprenger, 1991). Results were obtained from management
regarding their awareness of the necessity of deep cleaning, validation of cleaning
procedures and compliance with regulatory standards. Fifty percent were aware of the
necessity of the validation of cleaning procedures and compliance with regulatory standards,
with 37.5 % and 50 % responses in these categories, respectively (Table 4.2).
57
Table 4.1: Food safety assessment indicating compliance with food safety standards
in SANS 10330-2009 (Appendix A).
Risks/CCP assessment (Management)
Yes
%
n = 8
No
%
n = 8
Have you identified areas/process steps in
your facility that are critical to preventing
foodborne diseases?
5 62.5 % 3 37.5 %
Have you done a verification of the control
measures in place to control the critical
areas/process steps?
4 50.0 % 4 50.0 %
Have you done a validation of the process
steps that are critical? 3 37.5 % 5 62.5 %
Did you use a decision tree to identify critical
areas? 3 37.5 % 5 62.5 %
58
Table 4.2: Food safety assessment indicating compliance with general cleaning and
hygiene principles (Appendix A).
GMP/PRP assessment
(Management)
Yes
%
n = 8
No
%
n = 8
Does your facility comply to GMP
standards (SABS 049)? 4 50.0 % 4 50.0 %
Are your detergents SABS 1828
approved? 8 100.0 % 0 0.0 %
Is your sanitizer SABS 1853
approved? 7 87.5 % 1 12.5 %
Do you have a Master Cleaning
Schedule (MCS)? 6 75.0 % 2 25.0 %
Do you have a deep cleaning
procedure in place? 3 37.5 % 5 62.5 %
Do you verify your cleaning
efficiency by taking surface samples? 4 50.0 % 4 50.0 %
Has your staff had formal/external
hygiene awareness training? 8 100.0 % 0 0.0 %
59
4.4.2 Bacteriological safety of the food product
Only 75 % of the manufacturing plants made use of an official Master Cleaning Schedule
(MCS) as well as complied with the requirements stated in their policy document on a
monthly basis. However, correct responses about hand washing procedures ranged between
49 % and 51 % (Figure 4.1) and the results probably reflect a lack of commitment from the
workers. All of the manufacturing plants frequently send product samples for
microbiological analysis and 75 % did regular surface monitoring. Results from the
questionnaire showed that 25 % of the food plants contained samples that tested positive for
S. aureus, 50 % for Listeria and 37.5 % for E. coli (Table 4.3). According to Sagoo, Little
and Mitchell (2003), microbiological analysis of ready-to-eat salad vegetables from retail
outlets showed a direct relationship between management having received food hygiene
training, managements‘ confidence and food safety procedures being followed.
60
Figure 4.1: Hand washing procedures followed by food handlers (Appendix B).
0% 0%
49%
0% 0% 0% 0%
51%
100% 100%
51%
0%
100% 100%
0%
49%
0%10%20%30%40%50%60%70%80%90%
100%
ColdWateronly?
ColdWater
andSoap?
ColdWater,
Soap andSanitiser(alcohol)
ColdWater,Soap,
Sanitiser,Paper
towel andSanitiser
HotWateronly?
HotWater
andSoap?
HotWater,
Soap andSanitiser(alcohol)
HotWater,Soap,
Sanitiser,Paper
towel andSanitiser
Pe
rce
nta
ge (
%)
General hand washing practices
Yes
No
61
Table 4.3: Bacteriological risk assessment (Appendix A).
Bacteriological risk assessment
(Management) Yes
%
n = 8 No
%
n = 8
Do you have a microbiological
sampling programme? 8 100.0 % 0 0.0 %
Do you do regular surface
monitoring? 6 75.0 % 2 25.0 %
Do you do surface monitoring
during production? 4 50.0 % 4 50.0 %
Do you send samples for frequent
microbiological analysis? 8 100.0 % 0 0.0 %
Have you detected one of the following pathogen organisms on your final
product before?
Salmonella 0 0.0 % 8 0.0 %
Staphylococcus aureus 2 25.0 % 6 75.0 %
Listeria 4 50.0 % 4 50.0 %
Escherichia coli. 3 37.5 % 5 62.50 %
Do you do frequent
microbiological analysis of your
process water?
5 62.5 % 3 37.5 %
62
4.4.3 Knowledge and practices of food handlers
Fifty-six of the respondents (36.4 %) and 61 respondents (30.7 %) failed to select the correct
answer for the question about hand washing after blowing their noses and after smoking,
respectively (Fig 4.2). As indicated in Figure 4.2, the risk of workers introducing
microorganisms after rest periods or visiting the toilet signals a potential risk to the
consumer i.e. 13.6 % were found not to wash their hands after a rest period and 9.1 % did
not do so after visiting the toilet. Hands are a common carrier of bacteria that can cause
foodborne disease outbreaks. Ordinarily, these outbreaks relate to ineffective hand washing.
A study by Dag (1996) showed that the most common bad habits of workers at mass-
production food facilities were touching their mouth with their hands, using the same towel
to clean many places and to wipe their hands on their face or clothes while working. The
majority of food handlers and managers expressed a positive attitude towards food safety,
but this was not supported by self-reported practices and the observed discrepancy between
self-reported behaviour and actual behaviour (Ansari-Lari, Soodbakhsh & Lakzadeh, 2010).
The food workers had a good general knowledge of general sanitation measures in the
workplace. Hundred percent were aware of the need to wash their hands at the beginning of
every shift (Figure 4.2) and 100 % answered correctly on the need to properly clean surfaces
every day (Figure 4.3). However, various studies have shown that the efficacy of training in
terms of changing behaviour and attitudes to food safety is questionable (Mortlock, Peters &
Griffith, 1999).
63
Figure 4.2: Frequency of hand washing indicating non-compliance
of hand washing practices.
100.0%
86.4% 90.9%
63.6%
69.3%
0.0%
13.6% 9.1%
36.4%
30.7%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
Before eachshift?
After a restperiod?
Aftervisiting the
toilet?
Afterblowing
your nose orcoughing
Aftersmoking
Per
cen
tage
(%
)
Hand washing events
Yes
No
64
Figure 4.3: Food handlers‘ knowledge regarding specific personal and hygiene
procedures.
69% 66%
34%
100%
31%
34%
66%
0% 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Does yourcompany have
Personal HygieneProcedure
Have youreceived trainingin the Personal
HygieneProcedure
Have youreceived trainingin the cleaningprocedures for
the area youwork in?
How often do youclean the worksurfaces in your
area? Daily?
Pe
rce
nta
ge (
%)
Training evaluation
Yes
No
65
It seems that more workplace-specific courses should be planned for food workers, as
most training is currently done away from the workplace and the workers might find it
difficult to translate the theory into practice. The training courses also need some form
of evaluation to ensure their effectiveness (Miller & Osinski, 2002). In agreement with
various previous studies, the overall attitudes of the respondents were very positive
toward food safety measures, despite the fact that they had relatively poor hygiene
practices (Walker, Pritchard & Forsythe, 2003). The results of the present study
showed that with self-reported hygiene practices, only an average of 82 % of
respondents always washed their hands as a standard hygiene practice; 100 % at the
beginning of each shift; 86.4 % after a rest period; 90.9 % after visiting the toilet; 69.3
% after smoking; and 63.6 % after coughing and/or blowing their noses. Food workers
in many settings have been responsible for foodborne disease outbreaks for decades and
there is no indication that this is diminishing (Greig, Todd, Bartleson & Michaels,
2007). The general cleaning practices of the food handlers in their work environment
were further evaluated and the food handlers answered several questions (Appendix A).
Unfortunately, none of the manufacturing plants has an adequate supply of hot water to
be used for cleaning. A combination of cold water, soap, water pressure and sanitizer
are used in the practices generally applied. All of the plants use chemicals and/or
detergents for washing, but only 47.7 % (Table 4.4) use cold water, soap, pressure and
sanitizer, which comprise the best option.
66
Table 4.4: Food handlers‘ knowledge of good cleaning practices for work surfaces.
How do you clean your
working area?
(Production staff) n = 88
Yes % No %
Cold water only 0 0 88 100.0 %
Cold water & soap &
sanitizer 0 0 46 52.3 %
Cold water & soap &
pressure 0 100.0 % 88 0
Cold water & soap &
pressure & sanitizer 0 47.7 % 42 52.3%
Hot water only 0 0 88 100.0 %
Hot water & soap 0 0 88 100.0 %
Hot water & soap &
pressure 0 0 88 100.0 %
Hot water & soap &
pressure & sanitizer 0 0 88 100.0 %
67
General information regarding hygiene and sanitation
Of the respondents participating in this study, 66 % had received some form of food hygiene
training (Figure 4.3). Only 34 % received training from the chemical supplier on how to use
their products and training in the immediate areas they work in, but all of the workers were
aware that they have to clean their working environment daily (Figure 4.3). The
management of the eight manufacturing plants indicated that there are some obvious
problems in complying with the basic requirements of food safety stipulated in the Good
Manufacturing Practices Guide (South African Bureau of Standards, 2001). All eight plants
use SABS 1828-approved detergents that are non-toxic and safe for use in a food plant,
whereas 87.5 % (7 plants) use SABS 1853-approved sanitisers that carry the SABS mark on
the container. The one plant that does not use SABS 1853-approved products does so
because they cannot afford them and instead use an unformulated sodium hypochlorite
solution.
4.5 CONCLUSION
This study examined the beliefs of food handlers towards food safety and determined food
handlers' self-reported practices. This review particularly focused on studies that attempted
to evaluate the effectiveness of food safety and hygiene training. The results of the present
study showed that food workers in the eight manufacturing plants had an acceptable
knowledge level of good food hygiene practices, but relatively poor implementation thereof.
Despite the workers‘ good knowledge and attitudes toward food hygiene, their practices
were inadequate. Although food safety training programmes are essential, behavioural
changes will not occur merely as a result of training, thus should be further developed
through continuous programs and skills development. Evaluation of the programme‘s
impact is needed to show the merit of a programme and possible areas to change and/or
68
modify. The study further demonstrates that although food handlers may be aware of the
need for personal hygiene, they do not comprehend crucial aspects of hygiene.
69
4.6 REFERENCES
Ansari-Lari, M.A., Soodbakhsh, S. & Lakzadeh, L. (2010). Knowledge, attitudes and
practices of workers on food hygienic practices in meat processing plants in Fars, Iran.
Food Control, 21(3): 260-263.
Barrie, D. (1996). The provision of food and catering services in hospital. Journal of
Hospital Infection, 33(1): 13-33.
Baş, M., Ersun, A.S. & Kivanç, G. (2006). The evaluation of food hygiene knowledge,
attitudes and practices of food handlers in food businesses in Turkey. Food Control, 17(4):
317-322.
Centres for Disease Control and Prevention. (2004). Diagnosis and Management of
Foodborne Illnesses. Morbidity and Mortality Weekly Report 16/04/2004, 53(RR04): 1-33.
Available from http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5304a1.htm (Accessed 4
March 2011).
Centres for Disease Control and Prevention. (2005). Preliminary FoodNet data on the
incidence of infection with pathogens transmitted commonly through food—10 Sites, United
States, 2004. Morbidity and Mortality Weekly Report 15/04/2005, 54(14): 352-356.
Available from http://www.cdc.gov/mmwr/index2005.htm. (Accessed 19 October 2009).
Centres for Disease Control and Prevention. (2008). Surveillance for Foodborne Disease
Outbreaks. Morbidity and Mortality Weekly Report, 60(35): 1197-1202.
Clayton, D.A., Griffith, C.J., Peters, A.C. & Price, P. (2002). Food handlers‘ beliefs and
self-reported practices. International Journal of Environmental Health Research, 12(1): 25-
39.
70
Dag, A. (1996). Effect of hygiene training program developed for mass feeding services on
information, attitudes and behaviour. MSc thesis. Ankara, Turkey.
Doom, M. (2008). Poor Personal Hygiene Practices in a Restaurant and How to Protect
Yourself and Prevent a Food Poisoning! http://www.foodpoisoningprevention.com
Emery, H.C. (1990). Changing poor hand washing habits – A continuing challenge for
Sanitarians. Dairy, Food and Environmental Sanitation, 10(1): 8-9.
Ehriri, J.E. & Morris, G.P. (1996). Hygiene training and education of food handlers: Does it
work? Ecology of Food and Nutrition, 35: 243-251.
Gomes-Neves, E., Araújo, A.C., Ramos, E. & Cardoso, C.F. (2007). Food handling:
Comparative analysis of general knowledge and practice in three relevant groups in
Portugal. Food Control, 18: 707-712.
Greig, J.D., Todd, E.C., Bartleson, C.A. & Michaels, B.S. (2007). Outbreaks where food
workers have been implicated in the spread of foodborne disease. Part 1. Description of the
problem, methods, and agents involved. Journal of Food Protection, 70(7): 1752-1761.
Howes, M., McEwen, S., Griffiths, M., & Harris, L. (1996). Food handler certification by
home study: Measuring changes in knowledge and behaviour. Dairy, Food and
Environmental Sanitation, 16: 737-744.
Kaferstein, F.K., Motarjemi, Y. & Bettcher, D.W. (1997). Foodborne disease control: a
transnational challenge. Emerging Infectious Diseases, 3(4): 503-510.
Lues, J.F.R. & van Tonder, I. (2007). The occurrence of indicator bacteria on hands and
aprons of food handlers in the delicatessen sections of a retail group. Food Control, 18:
326-332.
71
McElhatton, A. & Marshall, R.J. (2007). Food safety: A practical and case study approach.
United States: Springer.
Miller J.A & Osinski D.M (2002). Training Needs Assessment. Retrieved on 17th
September 2009 from http://www.ispi.org/pdf/suggestedReading/Miller_Osinski.pdf
Mortlock, M.P., Peters, A.C. & Griffith, C. (1999). Food hygiene and hazard analysis
critical control point in the United Kingdom food industry: practices, perceptions and
attitudes. Journal of Food Protection, 62(7): 786-792.
Richardson, I.R. & Stevens, A.M. (2003). Microbiological examination of ready-to-eat
stuffing from retail premises in the north-east of England. The ―get-stuffed‖ survey.
Journal of Applied Microbiology, 94(4): 733-737.
Rogers, R. (2001). Handbook of Diagnostic and Structured Interviewing. New York:
Guildford Press.
Sagoo, S.K., Little, C.L., Mitchell, R.T. (2003). Microbiological quality of open ready-to-
eat salad vegetables: effectiveness of food hygiene training and management. Journal of
Food Protection, 66(9): 1581-1586.
South African Bureau of Standards. (2001). Code of Practice: Food Hygiene Management.
3rd
edition. (SABS 049: 2001).
Sprenger, R.A. (1991). Hygiene for management: a text for food hygiene courses.
Doncaster, UK: Highfield Publications.
Walker, E., Pritchard, C. & Forsythe, S. (2003). Food handlers‘ hygiene knowledge in small
food businesses. Food Control, 14(5): 339-343.
72
5. CHAPTER 5:
GENERAL DISCUSSIONS
5.1 INTRODUCTION
The popularity of convenience food is bound to increase with the growing appeal for food
that reduces/eliminates the preparation time. People‘s time is limited and convenience food
is the food of the future for the working mother. It is clear that managing foodborne disease
is a challenge and an economic problem subject to various constraints. This study
endeavoured to add to the understanding and contribute to the improvement of hand and
plant hygiene and the knowledge of food handlers in the Gauteng convenience food
industry. Senator Tom Harkin stated: ―That is both frightening and unacceptable to say that
food safety in this country is a patchwork system is giving it too much credit. Food safety
has too often become a hit-or-miss gamble, with parents obliged to roll the dice when it
comes to the safety of their children‘s food.‖ (Harkin, 2010). When Senator Harkin made
this comment, he was addressing issues in the United States of America, but his comment is
also applicable to other countries, including South Africa. Consumers in South Africa
nowadays demand good quality and safe products at a reasonable cost (Brand, 2008). The
industry therefore needs to improve processes to prevent the contamination of foods and use
methods to ensure safe food for consumers. To achieve this, training, more testing and
regular theoretical as well as practical testing (better methods of tracking food) must be
utilised to verify that the processes are working. This study endeavoured to add to the
understanding and improvement of hygiene processes as well as food handlers‘ practices in
the convenience food industry in the Gauteng Provence of South Africa.
73
5.2 COMPARISONS BETWEEN LOW-PRESSURE FOAM CLEANING AND
CONVENTIONAL CLEANING TO REMOVE SELECTED BACTERIAL
PATHOGENS FROM SURFACES ASSOCIATED WITH
CONVENIENCE FOOD
Chapter 2 of this study deals with the results of the comparison between low-pressure foam
cleaning and conventional cleaning of food contact surfaces in the convenience food
industry. The results obtained highlighted the presence of high counts of bacteria, including
one pathogen (Listeria), that were detected on the sanitized/disinfected convenience food
contact surfaces. The majority (59 %) of the Total Plate Count (TPC) samples exceeded the
specified requirements for food contact surfaces (< 100 cfu.cm-2
) of the Health Act
(Republic of South Africa, 1999). Even the plants that used SABS approved cleaning
chemicals and disinfectants/santisers still had a pathogen problem. Plants 1 and 7 had the
highest presence of Listeria and highest TPC results and both of these plants also made use
of conventional cleaning method. Plant 1 also had the only positive Escherichia coli
sample. Throughout the eight plants, the low-pressure foam cleaning method proved to be
more effective in controlling microorganisms than the conventional cleaning method. After
analysing and interpreting the results, it was clear that the food handlers who also act as
cleaners of their specific working environment do not have sufficient knowledge or adequate
equipment to apply the chemicals correctly or the chemicals are not as effective as stated to
achieve the desired results. It is strongly recommended that the management of the various
plants investigate the possibility of providing intensive training for the production workers
as well as oversee cleaning until the bacterial counts improve and comply with the
regulatory standards. This study has highlighted the fact that pathogens remain viable on
dry stainless steel surfaces and present a contamination hazard for considerable periods,
depending on the contamination levels and type of pathogen (Kusumaningrum et al. 2003).
74
There was a statistical relationship between the cleaning methods used and the TPC results
(P ≤ 0.05), but no statistical difference was found between the presence of Listeria and the
cleaning methods used.
5.3 MICROBIOLOGICAL CONTAMINATION ON THE HANDS OF
CONVENIENCE FOOD HANDLERS AS AN INDICATOR OF HAND
WASHING EFFICACY IN THE CONVENIENCE FOOD INDUSTRY
The microbiological quality of food can improve, especially with regard to contamination
from bacteria on hands, which may be transferred to the food during manual handling. The
study revealed that worker‘s hand hygiene in the convenience food industry is unsatisfactory
and underlines the need to improve the hygiene knowledge of food handlers, by focusing on
hand washing practices. Bacteria were found on 60 % of the samples taken by swabbing
workers hands and only 18 % of the hand samples taken showed no bacterial growth after
washing and sanitation processes had been performed. The hand soap and sanitisers used
were certified by the SABS and complied with the requirement of SABS 1853. These
findings indicate that sanitation protocols are not being applied in a way that will minimise
food safety in ready-to-eat manufacturing plants. Continuous training and follow up is
absolutely vital to ensure that the food handlers follow hand washing procedures to prevent
contamination of foodstuffs. Furthermore, the microbiological quality of employees‘ hands
can be used as an indicator to determine controls of the critical points for future Hazard
Analysis Critical Control Point (HACCP) systems. The results of the present study revealed
that, firstly, workers‘ hands can severely affect the microbiological quality of food. As
such, it is essential to identify weak points in general hand washing processes.
Contamination of the food handlers‘ hands poses a bigger risk to the product than
anticipated. Secondly, knowledge of these problems is essential to improving the control
75
systems of ready-to-eat food production establishments and to adjusting the staff training
programmes. Thirdly, training the workers in basic hand washing principles and the
validation of hand washing procedure and contact time should be considered, as the overall
results indicated that all the worker‘s hands in all eight ready-to-eat food manufacturing
plants involved in this study exceeded the legal requirements for food contact surfaces and
thus they potentially pose a risk to the consumer.
5.4 FOOD HYGIENE KNOWLEDGE AND PRACTICES OF FOOD
HANDLERS IN THE CONVENIENCE FOOD INDUSTRY IN THE
GAUTENG PROVINCE
In Chapter 4 of this study, a structured questionnaire was used to interview 88 food handlers
in the convenience food plants selected in Gauteng. The main foci were: the level of
managements‘ involvement in food safety, the product safety and the hygiene practices of
the food handlers. The results showed good/adequate knowledge on hygiene of the food
handlers in the eight manufacturing plants, but shortcomings in their attitudes and practices
(Clayton et al. 2002). Concerning results were obtained from management in convenience
food plants (62 %) who admitted that their awareness of the necessity of deep cleaning,
validation of cleaning processes and compliance with regulatory standards were lacking. It
seems that more workplace-specific courses should be planned for food handlers, as most
training is currently done away from the workplace and the workers might find it difficult to
translate the theory into practice. The questionnaire indicated that selected pathogens and
indicator organisms (Staphylococcus aureus, Listeria spp., E.coli) had been found on food
samples tested in the past. Compliance with the basic regulatory standards is one of the
obvious problems and this encompasses compliance with the standards for cleaning
chemicals used in food manufacturing plants for cleaning and sanitation. It is often
76
misunderstood that the sole responsibility of the government and its agencies is to provide a
legislative and regulatory framework to lay down certain mandates for those involved in the
provision of safe food to the consumer. As in most of the developing countries around the
world, South Africa has a very basic and undeveloped food legislatory system with multiple
problem areas, such as the existence of fundamental differences in agency missions and
approaches to inspection, non-uniformity of facilities, the unavailability of skilled personnel,
money wastage on non-essential issues and poor efforts being made in the development of
new technologies for controlling concerns. To an extent, it would be reasonable to say that
South Africa does not have an integrated food safety framework, but has a set of laws
dealing with selected aspects of food safety. Although laws have the potential to ensure
food safety standards, an absence in understanding and implementing them at all levels
leaves too many loopholes to be filled.
5.5 CONCLUDING REMARKS
Despite an increase in the number of food handlers receiving food hygiene training, a high
number of food poisoning outbreaks still occur as a result of improper food handling
practices in the general food industry. The implementation of the HACCP, ISO 22000
awareness, changes in the labelling legislation (Republic of South Africa, 2010) of
foodstuffs and the promulgation of the Consumer Protection Act (Republic of South Africa,
2008) have brought new responsibilities for food manufacturing plants. Not only is the
general population becoming more aware of the safety of food but also about the quality of
food that is sold to them. The current world economic climate and recession is forcing food
manufacturers to employ a cheaper labour force comprising people from lower income
groups with low levels of education and these people are now entrusted with preparing
ready-to-eat food, the most risky foodstuff available in the convenience market. These
77
employees‘ socioeconomic backgrounds may not necessarily support good hygiene
practices, as many of them come from informal settlement areas where there is a lack of
sanitation, proper housing and medical care.
5.6 RECOMMENDATIONS TO GOVERNANCE AND AUDIT BODIES
Microbiological guideline documents in South Africa are limited and as a result, very few
microbial standards are available. In addition, the enforcement appears to require
improvement. Future research can be conducted to compare international standards with
those available in South Africa. The South African Health Department should expand on
the available local list of microbiological standards as well as adopt globally accepted
standards to give the food industry and controlling bodies more information to work with
and measurable standards with which they can/must comply. The availability of more
comprehensive microbiological standards could serve as measurable objectives where
against the industry could compare itself to determine compliance and goals for
improvement.
5.7 RECOMMENDATIONS TO INDUSTRY
Management should be more aware of the hygiene standards in the industry and
enforce them and increase the focus on importance of adequate cleaning. Food
manufacturing plants deliver a basic necessity to people and it is essential that
the appropriate attention be given to hygiene and cleaning principles to ensure
safe food.
Proper, relevant and measurable training should be provided and continues
progress should be monitored.
78
External verification audits are vital to improving the overall hygiene in food
manufacturing plants and in creating awareness of problem areas.
Cleaning chemical suppliers, with the assistance of testing laboratories, should
be more involved in the validation of cleaning processes in food manufacturing
plants and more frequent sampling and validation of cleaning methods must be
done.
5.8 FUTURE RESEARCH
The following further research opportunities have been opened-up by the research:
A study on the prevalence of Listeria species in ready-to-eat manufacturing
plants and to determine why such levels exist.
Determination of the training required to train food handlers in better practices
and implementation.
Determination of the acceptable level of microorganisms on all working surfaces
as well as food handlers‘ hands.
A study to compare local microbiological standards with international standards
that will include all ready-to-eat products from all sectors of the food industry,
to improve and expand on the existing microbiological standards that are
available.
79
5.9 REFERENCES
Brand, J. (3 March 2008). Personal communication from Shoprite/Checkers.
Clayton, D. A., Griffith, C. J., Peters, A. C. & Price, P. (2002). Food handlers‘ beliefs and
self-reported practices. International Journal of Environmental Health Research, 12: 25-39.
Harkin, T. (2010). Harkin Floor Remarks on Food Safety. Available from
http://harkin.senate.gov/press/column.cfm?i=328631.
Kusumaningrum, H.D., Riboldi, G., Hazelger, W.C. & Beumer, R.R. (2003). Survival of
foodborne pathogens on stainless steel surfaces and cross-contamination to foods.
International Journal of Food Microbiology, 85(3): 227-236.
Republic of South Africa. (1999). Regulation 918 of 1999: Health Regulations governing
general hygiene requirements for food premises and the transport of food, promulgated
under the Health Act No. 63 of 1977. Pretoria: Government Printer.
Republic of South Africa. (2008). Consumer Protection Act No. 68 of 2008. Pretoria:
Government Printer.
Republic of South Africa. (2010). Regulation 146 of 2010: Regulations relating to the
labelling and advertising of foodstuffs, promulagated under the Foodstuffs, Cosmetic and
Disinfectant Act No. 54 of 1972. Pretoria: Government Printer.
80
APPENDIX A
81
APPENDIX A
An assessment of food safety risks associated with ready-to-eat foods from suppliers in
the Gauteng –area.
Questionnaire: Management
Thank you for taking part in this confidential survey. The aim of this survey is to determine
your practices regarding food safety at work. Your answers are confidential and will not be
used against you, as no names are recorded. The questions will be asked by the researcher
No. Questions Yes No
GMP/PRP (Management)
1. Does your facility comply to GMP standards (SABS
049)
2. Is your detergents SABS 1828 approved?
3. Is your sanitiser SABS 1853 approved?
4. Do you have a Master Cleaning Schedule (MCS)?
5. Do you have a Deep Cleaning Procedure in place?
6. Do you verify your cleaning efficiency by taking
swabs?
7. Has your staff had formal/external hygiene awareness
training?
Bacteriological risk assessment (Management)
8. Do you have a microbiological sampling programme?
9. Do you do regular surface swabs?
10. Do you send samples for frequent microbilogical
analysis?
11. Do you do surface swabs during production?
12. Have you detected one of the following organisms on
your final product before:
13. Salmonella
14. Staphyloccous aureus
15. Listeria
16. Escherichia coli
17. Do you do frequent microbiological analysis of your
process water?
Risks/CCP assessment (Management)
18. Have you identified areas/process steps in your facility
that is critical to prevent foodborne diseases?
19. Have you done a verification of the control measures in
place to control the critical areas/process steps?
20. Have you done a validation of the process steps that are
critical?
21. Did you use a decision tree to identify critical areas?
82
APPENDIX B
83
APPENDIX B
An assessment of food safety risks associated with ready-to-eat foods from suppliers in
the Gauteng –area.
Questionnaire: Production
Thank you for taking part in this confidential survey. The aim of this survey is to determine
your practices regarding hygiene at work. Your answers are confidential and will not be
used against you, as no names are recorded. The questions will be asked by the researcher.
How do you clean your working area (Production
staff)
Yes No
1 Cold Water only?
2 Cold Water & Soap & Sanitiser
3 Cold Water & Soap & Pressure
4 Cold Water , Soap & Pressure & Sanitiser
5 Hot Water only?
6 Hot Water and Soap?
7 Hot Water, Soap & Pressure
8 Hot Water , Soap & Pressure & Sanitiser
When do you wash your hands? (Production staff)
9 Before each shift?
10 After a rest period?
11 After visiting the toilet?
12 After blowing your nose or coughing
13 After smoking
How do you wash your hands? (Production staff)
14 Cold Water only?
15 Cold Water and Soap?
16 Cold Water, Soap and Sanitiser (alcohol)
17 Cold Water, Soap, Sanitiser, Paper towel and Sanitiser
18 Hot Water only?
19 Hot Water and Soap?
20 Hot Water, Soap and Sanitiser (alcohol)
21 Hot Water, Soap, Sanitiser, Paper towel and Sanitiser
Training (Production staff)
1. Does your company have Personal Hygiene Procedure
2. Have you received training in the Personal Hygiene
Procedure
3. Have you received training in the cleaning procedures
For the area you work in?
4. How often do you clean the work surfaces in your area?
Recommended